Season 1

Haruto Kirishima and Yuzuki Eba ride a bicycle through a dandelion field in Hiroshima as in the background he remarks that she was an unknown person at the time he met her, never having met her before or talked to her as well. Eventually, she jumps off the bicycle, fading into the background prompting Haruto to stop pedaling as he looks on noting that she left unforgettable memories when she left.

Haruto thinks back on how he and Yuzuki first met and the time they shared together back in Hiroshima.

A school festival gives Haruto the opportunity to meet Yuzuki face-to-face for the first time since he's arrived in Tokyo.

Just as the bonds of friendship begin to grow between Kazama and Haruto, a startling development threatens to ruin it.

When Haruto and Yuzuki were still together in Hiroshima, he learns that they'd actually first met when they were children.

Haruto learns the truth about Yuzuki's departure and her relationship with Kazama. Knowing this, he resolves to try and win her back.

A risky surgery could save Kazama's life, but will he go through with it despite the low chance of success?

Haruto has moved on and is dating his friend Asuka, but a chance encounter with Yuzuki causes familiar feelings to stir within him.

Rin mischievously sets Haruto and Yuzuki up on a date. Haruto's recent strange behavior causes Asuka to worry.

Asuka is forced to cancel her trip with Haruto. Haruto decides to go back to Hiroshima and ends up reconnecting with Yuzuki.

Yuzuki and Haruto relive their childhood memories. Reluctantly, Yuzuki confesses her true feelings to Haruto.

Haruto is torn. He finally realizes who he's in love with, but the thought of having to break someone's heart in the process torments him.