(it's just my canon where Rui and Tsukasa adopted Len!!)

Tsukasa and Rui they were married. they lived together and had an adorable little son, Len. the boy was very energetic, which made it difficult for Rui and Tsukasa to raise him.

Tsukasa was cooking dinner at home and Rui was working on something at garage. From time to time he looked at Len who was playing in the garden.