KIRIYAMA Rei is a 17-year-old professional shogi player who lives by himself in downtown Tokyo, where the bridges cross the rivers. He lost all his family in an accident when he was little, which has left a deep psychological scar within him. As people around him have high expectations of his talents as a shogi player, Rel ives a solitary life. Then the three sisters who live in the same town, Akari Hinata, and Momo, appear in his life, and as Rei comes in contact with them, a gentle story unfolds in which people start to regain something they have lost in their lives.