Future Diary
It turns out that Yuki, Yuno and ten other people who all have Future Diaries are part of a survival game, in which the group must kill each other using their diaries until one person is left alive. The winner shall become the next God of Time and Space after Deus dies. Yuno becomes Yuki's guard and would-be girlfriend as he makes friends and enemies of the other diary owners as the game moves on. Yuki does make friends with several children of his age including wannabe detective Aru Akise, Hinata Hino who is the daughter of the diary owner Karyuudo Tsukishima, Mao Nonosaka who loves Hinata, and former bully Ouji Kosaka.