Kanata Haruka lost both of his parents and is left alone in the world without any relatives. On top of this he was diagnosed with terminal cancer and told that his remaining time on earth would not last long enough for him to see springs cherry blossoms again.

The only pillars of support in his life are his two childhood friends: Kousuke and Kanae. Kousuke heard about Kanata's illness and started helping him with all kinds of chores as these became increasingly more difficult for him to complete on his own because of the immense side effects brought on by the anticancer drugs. However, Kanata could not bring himself to also tell Kanae about his condition who he noticed was in love with him.

The seasons gradually become colder moving from late autum to early winter, when suddenly a blonde haired girl makes an appearance in Kanata's house. She introduces herself as Christel, an immortal vampire...