If you're looking for manga similar to Kanon & Air Sky, you might like these titles.
In the near future. In a not so distant place. There exists a society where law is based upon deterrence and criminals are assigned "obligations" fitting for their crimes. Within this society, a man named Morita Kenichi aspires to the position of Special High Class Individual, one who holds authority over said criminals. For the purpose of fulfilling his ambition, Kenichi returns to the town he once called home. There he will encounter three girls bearing "obligations" and the past he left behind. Won't you join him in this story about how people relate to their society?
Tetsuya Mizuno, a third year high school student, meets Yuzuko Sanada, a childhood friend whom he nicknamed Yuzu one day on his way to school. Yuzuko actually has a crush on Tetsuya. To her advantage, she is skilled at cooking and homemaking, but has a timid personality. He later also meets Rui Nakane at the pool after running errands for Asumi Akiyam, his cousin who is also the school nurse. Rui holds vast knowledge, and is very affectionate towards animals to the extent where her aim is to become a veterinarian. Despite her love toward animals, she has a severe fear of touching cats due to a past incident...