“Yuto” laid on the butt of his super-high-flying sister-in-law “Erika” is a sibling with no blood connection.
The relationship between these two people changes into emotions that are close to romance over time.
However, the school teacher “Sayaka Ichinose” notices the relationship between the two.
The love triangle between Erika and Sayaka who seek Yuuto from each other unexpectedly develops … !!