Before appearing as the Stage 5 Boss of QP Shooting, Store Manager first appeared as the final boss of a game made by Hono in 2002, called Mid Night Pleasure.[1]
Store Manager was once stated to be a sweet god, Sweet Cooker. Although, this is probably a joke or retconned later by Hono.[2]
Prior to Version 1.15, Store Manager had no music theme of its own; when leveling up, QP's theme ▶️ was played instead.
Completion Reward. It also appears in the artwork for 
Sky Restaurant 'Pures', 
Unpaid Work, 
Overtime, 
Banned for Life, 
Overseer, and 
Manager, I Could Use Some Help!.