For two years, snow had been falling continuously in the town of Tsukigasaki with spring nowhere in sight. Aside from the snow which never built up, the town was also struck by other abnormal incidents, such as tornadoes, thunderbolts and floods. Riku is an ‘elfin’ who possesses a mysterious ability known as ‘rune’, which he uses to save others. He returned to Tsukigasaki, where he grew up in an orphanage, along with fellow elfins Rinne and Hinata. Their duty was to protect two young sisters, Ochiba and Hazuki, from rune abilities which go out of control, while also keeping the existence of elfins a secret to the public. When he arrived at the town, a girl in a pure white dress was waiting for him. He used to play with the girl Yuuki when they were small, having snowball fights and making snowmen. To his surprise, she still looked exactly the same as before he left. While she’s sad that the city has since changed a lot, she told him that he still remained the same to her even if he grows up.