Iriya no Sora, UFO no Natsu (Iriya’s Sky, Summer of the UFOs) is a poignant, quiet masterpiece that tells a story of first love against the backdrop of an unspoken war. The narrative follows Naoyuki Asaba, a high school student who meets Kana Iriya, a mysterious and reclusive girl. He soon discovers that Iriya is a skilled fighter pilot, the last line of defense in a secret war against an alien force, and that she carries the immense burden of being humanity’s final hope.
The series is defined by its core themes: a power system rooted in advanced, secretive military technology where the cost of power is immense personal sacrifice. The protagonists are profound underdogs—not in a physical sense, but as teenagers utterly powerless against the machinations of the adult world and the cruel demands of duty. Iriya no Sora masterfully subverts expectations by presenting what appears to be a gentle school-life romance and slowly revealing a deep, melancholic sci-fi tragedy about isolation, trauma, and the desperate search for normalcy in a life defined by war. It is a short, emotionally devastating OVA series that lingers in the memory like a half-remembered summer.
For fans of Iriya no Sora, UFO no Natsu, finding similar anime can be a challenge. The series occupies a unique space—part school romance, part military sci-fi, part quiet character study. Yet, many underrated series share its core DNA: a focus on the emotional cost of being different, a relationship built on shared secrets and mutual understanding, and a willingness to explore the quieter, more melancholic side of science fiction. These shows deserve far more attention for their emotional depth, their understated power, and their ability to find profound beauty in the midst of sorrow.
Here are 15 underrated anime that capture the spirit of Iriya no Sora, UFO no Natsu.
1. Saikano (She, The Ultimate Weapon) (2002)
- Streaming Availability: Not currently available on major platforms.
- Rating: MAL: 7.3
- Episodes: 13
- Studio: Gonzo
- Notable Staff: Based on the manga by Shin Takahashi.
Plot Summary: Shuji and Chise are high school students in a small town, trying to maintain a normal relationship while a world war rages in the background. Their lives are shattered when Shuji discovers that Chise has been transformed into a powerful weapon by the military.
Similarities to Iriya no Sora: Both are tragic love stories about a girl who is transformed into a weapon of war, and the boy who loves her. The focus is on the emotional devastation of being used as a tool for destruction and the desperate attempt to cling to normalcy. The tone is profoundly melancholic, and the relationship is the heart of the story.
2. Voices of a Distant Star (Hoshi no Koe) (2002)
- Streaming Availability: Crunchyroll
- Rating: MAL: 7.6
- Episodes: 1 (Short Film)
- Studio: CoMix Wave Films
- Notable Staff: Created, directed, and animated almost entirely by Makoto Shinkai (Your Name).
Plot Summary: Mikako Nagamine is chosen to be a mecha pilot in a war against an alien race, while her close friend Noboru Terao remains on Earth. As Mikako travels further into space, their text messages take longer and longer to reach each other, stretching their bond across light-years.
Similarities to Iriya no Sora: Both are about a young couple separated by an interstellar war, where the girl is the one fighting on the front lines. The focus is on the ache of separation and the power of simple messages to bridge vast distances. The melancholic tone and the focus on the emotional weight of a single relationship are a direct parallel.
3. The Place Promised in Our Early Days (Kumo no Mukou, Yakusoku no Basho) (2004)
- Streaming Availability: Crunchyroll, Amazon Prime Video
- Rating: MAL: 7.6
- Episodes: 1 (Film)
- Studio: CoMix Wave Films
- Notable Staff: Directed by Makoto Shinkai.
Plot Summary: In an alternate post-war Japan divided into two zones, three friends—Hiroki, Takuya, and Sayuri—make a promise to fly to a mysterious tower on the other side of the border. Years later, Sayuri has fallen into a coma, and the tower holds the key to waking her.
Similarities to Iriya no Sora: Both are set against the backdrop of a secret conflict and focus on the emotional bonds between teenagers caught in the gears of larger forces. The girl, Sayuri, is connected to the war in a way she cannot control, much like Iriya. The film is a quiet, melancholic meditation on memory, longing, and the promises we make.
4. Now and Then, Here and There (Ima, Soko ni Iru Boku) (1999)
- Streaming Availability: HiDive
- Rating: MAL: 8.0
- Episodes: 13
- Studio: AIC
- Notable Staff: Directed by Akitaro Daichi.
Plot Summary: Shu, an ordinary boy, is transported to a dystopian world where water is scarce and children are forced to become soldiers. He is captured and must survive the brutality of this world while trying to protect a mysterious girl named Lala-Ru, who possesses a powerful pendant.
Similarities to Iriya no Sora: Both are unflinching explorations of the cruelty of war and the exploitation of children as weapons. The protagonist is an underdog who must maintain his humanity in the face of overwhelming evil. The relationship between Shu and Lala-Ru mirrors the bond between Naoyuki and Iriya, built on a desperate desire to protect.
5. Air (2005)
- Streaming Availability: Funimation
- Rating: MAL: 7.3
- Episodes: 12
- Studio: Kyoto Animation
- Notable Staff: Based on the visual novel by Key, directed by Tatsuya Ishihara.
Plot Summary: Yukito Kunisaki, a traveling performer, arrives in a quiet seaside town searching for the “girl in the sky,” a figure from his family’s history. He meets Misuzu Kamio, a lonely and eccentric girl, and their fates become intertwined with a thousand-year-old curse.
Similarities to Iriya no Sora: Both are set during a single summer and feature a relationship between a boy and a mysterious girl who is burdened by a fate she cannot escape. The supernatural elements are tied to the girl’s identity and her isolation from the world. The tone is profoundly melancholic, and the focus is on the beauty of fleeting moments.
6. Haibane Renmei (2002)
- Streaming Availability: Funimation
- Rating: MAL: 8.0
- Episodes: 13
- Studio: Radix
- Notable Staff: Created by Yoshitoshi ABe (Serial Experiments Lain).
Plot Summary: Rakka, a newly born “Haibane,” awakens in a strange, walled town with small wings and no memory of her past. She and the other Haibane are forbidden from leaving and must live a quiet, simple life while grappling with their existence and the nature of their “sin.”
Similarities to Iriya no Sora: Both are quiet, atmospheric series about isolated individuals searching for meaning and connection. The protagonists are underdogs in a world they don’t fully understand, and their journey is one of introspection and healing. The focus on the emotional weight of existence and the search for belonging is a direct thematic parallel.
7. Mushi-shi (2005)
- Streaming Availability: Crunchyroll, Hulu
- Rating: MAL: 8.7
- Episodes: 26 (Season 1)
- Studio: Artland
- Notable Staff: Based on the manga by Yuki Urushibara.
Plot Summary: Ginko, a “Mushi-shi,” travels the countryside investigating “Mushi”—primordial, ethereal lifeforms that exist alongside humanity, often causing inexplicable and sometimes harmful phenomena. His journey is one of quiet observation, understanding, and finding balance.
Similarities to Iriya no Sora: Both share a quiet, contemplative tone and a focus on the unseen forces that shape human lives. The “Mushi” are a metaphor for the mysteries of existence, much like the alien threat in Iriya no Sora is a backdrop for exploring human emotion. The focus is on understanding and acceptance, not action or conflict.
8. Kino’s Journey (2003)
- Streaming Availability: Amazon Prime Video, HiDive
- Rating: MAL: 8.3
- Episodes: 13
- Studio: A.C.G.T.
- Notable Staff: Based on the light novel series by Keiichi Sigsawa.
Plot Summary: Kino, a young traveler, journeys with a talking motorcycle named Hermes through a variety of strange and unique countries, each with its own distinct culture, technology, and philosophy. Kino’s rule is to stay in each country for only three days and two nights.
Similarities to Iriya no Sora: Both are philosophical journeys presented in an episodic format, exploring the complexities of human nature and society. The tone is quiet, observational, and often melancholic. The focus is not on action but on understanding different perspectives and the often-uncomfortable truths about the world.
9. Planetarian: The Reverie of a Little Planet (2016)
- Streaming Availability: Funimation
- Rating: MAL: 7.7
- Episodes: 5 (ONA)
- Studio: David Production
- Notable Staff: Based on the visual novel by Key, directed by Naokatsu Tsuda.
Plot Summary: In a post-apocalyptic world where humanity has been destroyed by war, a lone scavenger stumbles upon a functioning planetarium. Inside, he meets Yumemi, a cheerful robot who has been waiting for customers for thirty years, unaware that the world has ended.
Similarities to Iriya no Sora: Both are short, emotionally devastating stories about a connection formed in the midst of a larger tragedy. The focus is on the relationship between two lonely individuals and the search for beauty and hope in a broken world. The melancholic tone and the focus on the power of simple moments are a direct parallel.
10. 5 Centimeters per Second (Byousoku 5 Centimeter) (2007)
- Streaming Availability: Crunchyroll
- Rating: MAL: 7.7
- Episodes: 1 (Film, divided into 3 parts)
- Studio: CoMix Wave Films
- Notable Staff: Directed by Makoto Shinkai.
Plot Summary: The film follows Takaki Tono and Akari Shinohara, two close friends who are separated by distance. It explores their relationship over the years, focusing on the ache of separation, the passage of time, and the fading of first love.
Similarities to Iriya no Sora: Both are profoundly melancholic stories about the distance between people and the passage of time. The focus is on the beauty and pain of memories, and the acceptance that some connections are destined to fade. The atmospheric, visually stunning presentation and the quiet, emotional tone are a direct match.
11. Kanon (2006)
- Streaming Availability: Crunchyroll, Funimation
- Rating: MAL: 7.9
- Episodes: 24
- Studio: Kyoto Animation
- Notable Staff: Based on the visual novel by Key, directed by Tatsuya Ishihara.
Plot Summary: Yuuichi Aizawa returns to a town he lived in seven years ago, but he has lost all memories of the time he spent there. He reconnects with several girls, each of whom is connected to his forgotten past in a way that is often tragic and mysterious.
Similarities to Iriya no Sora: Both are Key-adjacent works that share a deep focus on memory, loss, and the enduring power of love. The structure of a male protagonist encountering a mysterious girl with a hidden burden is similar. The winter setting of Kanon provides a similar atmospheric weight to the summer setting of Iriya no Sora.
12. She and Her Cat: Everything Flows (Kanojo to Kanojo no Neko: Everything Flows) (2016)
- Streaming Availability: Crunchyroll
- Rating: MAL: 7.6
- Episodes: 4
- Studio: Liden Films
- Notable Staff: Based on the original short by Makoto Shinkai, directed by Kazuya Sakamoto.
Plot Summary: The story is told from the perspective of a cat named Daru, who lives with a young woman struggling with the challenges of adulthood and loneliness. The series follows their quiet, everyday life together, finding beauty in the simple moments of companionship.
Similarities to Iriya no Sora: Both are quiet, intimate stories about the search for connection and the comfort of companionship. The focus is on the small, everyday moments that give life meaning. The melancholic but warm tone is a perfect match for the emotional register of Iriya no Sora.
13. Sola (2007)
- Streaming Availability: Crunchyroll
- Rating: MAL: 7.1
- Episodes: 13
- Studio: Nomad
- Notable Staff: Original story by Naoki Hisaya, a key writer for Kanon.
Plot Summary: Yorito Morimiya is a young man who loves to photograph the sky. He meets Aono, a mysterious girl who is connected to a supernatural secret involving the night sky and a creature known as a “Yaka.” Their meeting sets off a chain of events that reveals hidden truths about their pasts.
Similarities to Iriya no Sora: Both are supernatural dramas with a focus on the sky as a central motif. The protagonist is a relatively ordinary boy who meets a mysterious girl with a hidden burden. The series explores themes of loneliness, sacrifice, and the enduring power of love, with a melancholic, atmospheric tone that is a direct match.
14. Ef: A Tale of Memories (2007)
- Streaming Availability: HiDive
- Rating: MAL: 7.9
- Episodes: 12
- Studio: Shaft
- Notable Staff: Based on the visual novel by minori, directed by Shin Oonuma.
Plot Summary: The story is told through two interconnected narratives: Hiro Hirono, a manga artist, and his relationship with Miyako Miyamura, and Renji Asou, who meets a girl named Chihiro Shindou who can only remember thirteen hours at a time. Both stories explore the fragility of memory and the power of love.
Similarities to Iriya no Sora: Both are visual novel adaptations that share a deep focus on memory, loss, and the search for connection. The Shaft animation style is unique and visually striking, adding to the dreamlike, melancholic atmosphere. The themes of loneliness and the struggle to hold onto precious moments are a direct parallel.
15. Glasslip (2014)
- Streaming Availability: Crunchyroll
- Rating: MAL: 5.8
- Episodes: 13
- Studio: P.A. Works
- Notable Staff: Directed by Junji Nishimura.
Plot Summary: Touko Fukami is a young girl who lives in a small seaside town and has the ability to see glimpses of the future through fragments of glass. Her quiet life is disrupted by the arrival of a transfer student, Kakeru Okikura, who claims to hear voices from the future.
Similarities to Iriya no Sora: Both are quiet, atmospheric series set in a small town, with a focus on a group of teenagers and the emotional currents that run beneath their everyday lives. The supernatural elements are subtle and understated, serving as metaphors for the characters’ inner struggles. The series is a contemplative exploration of youth, identity, and the passage of time.
Why These Anime Work for Iriya no Sora, UFO no Natsu Fans
Fans of Iriya no Sora, UFO no Natsu are drawn to stories that are quiet, melancholic, and emotionally devastating. They appreciate a narrative that focuses on the emotional cost of being different, the weight of duty, and the search for connection in a world that is often cruel and indifferent. They are not looking for explosive action or heroic victories, but for the quiet, intimate moments that define a life.
The anime listed above all share this fundamental DNA:
- Power as a Burden, Not a Gift: Whether it is the ability to pilot a UFO, the curse of being a weapon, or the ability to see the future, these series understand that power comes with a terrible cost. The protagonists are not empowered by their abilities; they are burdened by them, and their struggle is to find a way to live with that burden.
- The Emotional Underdog: The protagonists are not heroes in the traditional sense. They are ordinary people who are caught in extraordinary circumstances, and their strength lies not in their power, but in their capacity for love, empathy, and resilience.
- Subversion of the Sci-Fi Genre: These series use the trappings of science fiction—war, aliens, advanced technology—not for spectacle, but for exploring the human condition. They understand that the most profound stories are often the quietest ones, and that the greatest battles are fought within the heart.
These 15 anime, like Iriya no Sora, UFO no Natsu, are not afraid to be quiet. They trust their audience to appreciate the weight of a single glance, the meaning of a single word, and the profound impact of a single summer. They are underrated gems that offer a deeply moving and unforgettable experience for viewers who are willing to open their hearts to the bittersweet beauty of life.
