Ayase Haruka stars in the upcoming film Hito wa Naze Love Letter wo Kaku no ka (Why Do People Write Love Letters), directed by Ishii Yuya, known for acclaimed works such as The Great Passage, Moon, and The Vancouver Asahi. The film is set to premiere on April 17 and revisits the tragic 2000 Tokyo Metro Hibiya Line derailment near Nakameguro Station, using the incident as the backdrop for a moving exploration of memory, loss, and unspoken affection.
The cast includes Toma Ami, Hosoda Kanata, Tsumabuki Satoshi, Suda Masaki, and Sato Koichi, forming a strong ensemble that reinforces the film’s emotional weight.

The story begins with Tomihisa Shinsuke (played by Hosoda), a high school student from an elite school who is devoted to boxing. Commuting daily on the same train, Terada Nazuna (Toma) gradually falls for him despite not knowing his name. Their quiet routine collapses when Shinsuke boards the train at a slightly different time one morning, becoming one of the accident’s victims at just 17. When Nazuna sees his name on the news, she refuses to accept the truth and spends days searching for him on trains, hoping for a miracle.
Twenty years later, Ohashi Hideyuki, head of the boxing gym Shinsuke frequented, receives a message from a stranger—the girl who once admired the boy in silence. Nazuna (portrayed by Ayase) now lives in the suburbs with her husband (Tsumabuki) and daughter and runs a small eatery. A sudden event stirs her long-suppressed memories, leading her to pick up her pen and write letters as a way to reclaim and preserve what time has eroded.
The supporting cast includes Otoo Takuma, Tomita Miu, Nishikawa Airi, Kasahara Hideyuki, Tsuda Kanji, and Hara Hideko, enriching this delicate narrative.
Why Do People Write Love Letters is a cinematic love letter itself—one addressed to youth, fate, and the lingering emotions that never fade, inviting viewers to reflect on the words they once wished they had written.