Pita-Ten Box Set: v. 1 by Koge Donbo
Kotarou Higuchi is an elementary school student whose mother died and father is often away on business. He is doing his best - and failing - to pass the entrance exams for middle school. His life is made even harder when his new neighbour Misha wont leave him alone. She claims that she is an angel and will do her best to protect him.