Gratin | ぐらタン

Haruki used to live with his mother, but now moves in with his relatives: 4 sisters born from 4 different mothers, but the same father. Their father was a traveling magician who used magic on them before disappearing. There is only one way to remove the magic: all 5 of them must build a close family bond to each other. However, can Haruki resist temptation being with such cute girls and view them as just family?