Shogo Mikadono is the son of an industrial magnate named Kumagoro Mikadono who passed away. As a final wish, Kumagoro imposed a condition Shogo must meet before he can inherit the family legacy—find a female mate at school. Shogo transfers into a school to fulfill that condition. However, he learns that he has a younger sister from whom he was separated at birth. He does not know what his long-lost sister looks like, but she happens to be one of the students at his new school.
During his father’s funeral, Shogo hears a voice outside his window claiming to be his little sister, before he has a chance to learn more, he is told the conditions of his inheritance.
After the mysterious phone call the person claiming to be his sister, Shogo school life gets more hectic with the arrival of a new transfer student.
The question of Shogo's sexual preference is causing Miyabi and Rinka to go overboard on showing the appeals of a woman.
Shogo has ruined his relationship with Miyabi; after letting Konoe know about his secret, a new problem has arisen.
He thought it was over but his little sister keeps calling. Shogo discovers someone else has the same prototype phone as Konoe.
Lyrical Sisters is on the verge of shutting down, Shogo puts together and executes a plan worthy of the Mikadono name.
Using the school broadcast system, Shogo’s “sister”, has requested he stops looking for her or she will reveal damaging secrets.
Kunitachi might be the Shogo’s sister but he can’t get close to her. Ikusu suggest that Shogo and Kunitachi spend time outside the school to have her drop her guard.
Shogo is getting a new neighbor and an unexpected surprise.
When all of Shogo’s potential wives are invited to the same party, things do not go as planned. Especially when he finds a trusted member is planning to overthrow his inheritance of the company
With all the lies, conflicting stories, and people trying to ruin his inheritance, Shogo is breaking down. To add to his worries, Kannagi is making outrageous demands.
With the help of Ikusu, Shogo has finally put the clues together on who his real sister is.