Bokura wa Minna Kawai-sou

Thanks to his parents' job transfer, high school freshman Kazunari Usa finally gets to enjoy living on his own. His mother makes him stay at Kawai Complex, a boarding house that provides meals for its residents. Ritsu, the senpai he admires, also lives in Kawai Complex, as do a few other "unique" individuals: Shirosaki, his novelist, masochistic roommate; Mayumi, a beautiful, buxom office lady who has terrible luck with men; and Sayaka, a sly and predatory college student. Surrounded by these people, Usa finds his daily life neither peaceful nor boring. As the series progresses, Usa and Ritsu gradually become closer friends, and the pair's feelings for each other grow stronger. After a series of misunderstandings, including Usa's belief that Ritsu has developed feelings for a classmate and her thinking that he is kind to her out of pity rather than genuine caring, the two eventually become a couple towards the end of Usa's second year in high school. (Source: Wikipedia)