Chichi to Higegorira to Watashi

Synopsis

After losing her mother to a tragic accident, 6-year old tomboy, Michiru, finds a suspicious person moving into her precious home: her dad’s giant younger brother Kouji, the “Beard Gorilla”. While awkward at first, it doesn’t take long for the two to develop a familiar bond that looks more like that of a brother and a sister, than that of niece & uncle. Source: Manga Updates