Quartet

18-year-old Hirosaki Naoya's mother has just gotten remarried. Naoya and his little brother and sister move in with their new stepsister, the beautiful young office worker Yukari, while their parents are on their honeymoon. The four of them are eager to build a new household together.

Note: chapter count includes 3 one-shots:
- Kyou no Obentou to Nan daro na
- Natsuiro no Omoide
- Choukan