Natsuo is a high school boy who is experiencing the crushing despair of unrequited love. To make matters worse, the person he is in love with is his teacher, Hina. In an attempt to lift his spirits, he attends a mixer where he meets a girl named Rui. The two sleep together, expecting never to see one another again, but fate has other plans. His life suddenly becomes more complicated when his father comes home and announces he has remarried a woman with two daughters whom Natsuo has met before: Hina and Rui!
Natsuo's life suddenly becomes more complicated when his father comes home and announces he has remarried a woman with two daughters whom Natsuo has met before. They're Hina, his teacher and unrequited crush, and Rui, a girl he previously slept with.
Natsuo has mixed feelings about a new classmate. Later, Hina receives a mysterious call that leaves her emotional and Natsuo concerned.
Natsuo learned the truth about Hina's mysterious relationship. Following an intense encounter with her, Natsuo leaves home to cool off and establishes a connection with Rui.
Determined to end Hina's affair, Natsuo and Rui take matters into their own hands. But things don't go according to plan.
Rui makes a new friend with a notorious reputation - and an uncomfortable attraction to Natsuo.
Crime doesn't pay and the punishment doesn't always fit the crime - a lesson Natsuo experiences firsthand after 'borrowing' a book from the library.
Natsuo's perception of Hina changes when she reveals how she first met Shuu. Later, Rui comes to Natsuo with a surprising request - one he isn't sure he should fulfill.
You can only lie to yourself for so long. As truths come bubbling to the surface, consequences ripple through Natsuo's entire household.
Hina puts her plan to move out into motion. Neither Rui nor Natsuo wants her to leave, albeit for different reasons. Will their home feel the same without Hina in it?
Natsuo takes a tumble down a flight of stairs, but a broken leg is the least of his worries when he's caught in a lie by Rui.
Rui makes a decision after her conversation with Natsuo. Later, Natsuo's class takes a field trip to Okinawa, where feelings are laid bare beneath the light of fireworks.
When the unthinkable happens, Hina expresses her love for Natsuo the only way she can: by giving him a chance to move on.