Season 1

Kazushi, a university student living alone, is troubled by the presence of two childhood friends, sisters, who hang out all the time at his apartment. The cheeky older sister, Ayane, and the laid-back younger sister, K…

That night after their secret affair in the bathroom, Kazushi is unable to sleep due to excitement and feelings of guilt. While Kazushi is like that, Kotone and Ayane are sleeping soundly in a row as usual. Inspired by…

The day after a depraved night with his sisters, Kazushi is walking along, reflecting on the events of the previous night, when Ayane, with whom he now has the most awkward relationship, appears before him. When Kazus…

"Huh... you were lonely without me...?" Ayane and Kazushi are finally alone at the sports festival, where they go to cheer on their sisters, and the atmosphere is good...! But then Ayane's classmates enter the girls' …

"Because you're like family to me... I can always be by my big brother's side," Kotone mutters sadly as she steals Kazushi's lips. As the sports festival draws to a close, Kazushi learns the girl's true feelings in an…

Kazushi and the Shirakawa sisters decide to go to the pool on the substitute day off for the sports festival. Ayane, who has been tasked with preparing the lunch boxes, finds herself standing in Kazushi's kitchen weari…

"My swimsuit is... gone!?" Kotone's bikini falls off the moment she slides down the water slide at the pool. Kazushi quickly hides her chest and runs into the storehouse, but the sight of the two of them alone topless…