Kirarincho's Ghost Festa (キラリンチョのおばけフェスタ, Kirarincho no Obake Festa) is a children's book by Yoshio Sawai. Kirarincho is the prince of the Ghost Kingdom. As a ghost, he's rather good at scaring people silly. However, that's not quite the kind of silly he has in mind...
Seven-year-old Rika Midou is sent to Sunny Bell Academy, a children's foster home. Neglected in single-parent household, Rika seems innocent at first glance, but the staff notices signs of dark shadows in her past. Various troublesome incidents start occurring. The director, Tokugawa, quietly observes the situation...! This is a shocking work that reveals the problems related to the care and education of abused children! (Source: Kurage Bunch, translated)
Guy reincarnates in another world and his support angel reincarnates with him as his sister. Strangely enough, she begins to teach him magic with great excitement, until she gradually begins to laze around and he discovers her end goal was just to build him up enough so that she can leech off of him for life.

