Sub Manager (店長代理 Tenchō Dairi), known as Assisticat in the English dub, is Misaki and Shin Nitta's pet cat that does some certain tasks in Card Capital, like watching over the counter while Misaki is away. He is usually left to take care of Card Capital in recent scenarios, where Shin and Team Q4 went for the Regional Tournament and the National Championship. He occasionally stays on the counter next to Misaki and is sometimes naughty but spends most of his time asleep. It is shown that he is resentful of being called 'Sub Manager' and prefers 'Manager', which shows he will only do tasks when called this. It is shown that he understands when humans speak, for example in episode 11, Sub Manager seemed to tell Emi about the no food/drink rule in the shop (Misaki made a joke about understanding cat language) but the Sub Manager also answered Emi's question to it with a meow.
He is voiced by Izumi Kitta.