Aishigatari Monomanie

1-3, 7. Aishigatari Monomanie
Higuchi Yuuya has been adopted by the son of the woman who caused an accident that killed his parents, Saeki Tooru. Both agree to live as a 'family.' As time flies by, both have developed feelings that can't be explained.
4-5. Himitsu Yuukaiten
6. Junketsu Sentimental