It should focus on at least three of the following characters and show them living together in some way, whether that's obviously being at the shrine or doing chores like grocery shopping etc. together.
Yorigami Shion, the poverty god. Stayed with Reimu for a time towards the end of Antinomy of Common Flowers while her sister was sent to train at Myouren Temple
Genjii, Reimu's old turtle familiar and mentor. Not usually depicted in the modern era of Touhou, and currently stated to be living in a pond near the Shrine, but can show up occasionally.
Sendai Hakurei no Miko, a fan character depicted either as Reimu's predecessor or mother.
Visitors
Sunny Milk, Star Sapphire and Luna Child, the Three Fairies of Light, who live in a tree behind the shrine, close to the Great Hakurei Barrier. Like the frolicking Fairies pool, any combination of them only counts as one person to prevent the pool being flooded with them.
Kirisame Marisa, who hangs out at the shrine frequently. Often depicted as a resident herself.
Ibaraki Kasen, the Wild and Horned Hermit, who visits frequently to monitor Reimu's progress and behaviour. Often shown as either a mentor, a mother figure, or both.
Yakumo Yukari, another mentor/mother figure, who only drops in occasionally.
Kaenbyou Rin, who frequently invites herself over. Often treated as a rival pet to Aunn.
Mima, a PC-98 character who was repeatedly sealed at the shrine (and who repeatedly broke out over and over again).
Characters who only move to the Hakurei Shrine in one of Phantasmagoria of Dim.Dream's various endings. As these endings are largely mutually exclusive (and none of these characters have ever appeared outside of Dim.Dream), they are almost never included except in the most comprehensive of sets.
