After a period of time with Nookington's, Tom Nook will ask the player a question to better serve his customers. Based on the answer they give, Nookington's can close and reopen as a previous store to better suit their needs. Periodically, after the first questioning, Tom Nook will ask again, and the player can change their store again. This event only happens in City Folk.

In New Leaf, however, Tom Nook has become a real estate agent, leaving the management of his store, now known as Nookling stores, to his "nephews", Timmy and Tommy. The responsibility of welcoming new players has been given to Isabelle. Like in previous games, Tom will be responsible for orchestrating the construction of the player's house and providing the mortgage the player pays off via the ABD machine in the Post Office. Tom Nook runs a real estate agency called Nook's Homes, which also provides house customization and renovation services. The office also functions as the headquarters of the home inspection organization, the Happy Home Academy, run by Lyle. Tom Nook also assists the player in searching for a plot to build their house when they first move in. Once a plot has been chosen, he will pitch his tent for the player to use as temporary housing while they are gathering funds to pay off their first home loan. Tom Nook's agency is also responsible for building the house's neighbors live in, as well as assisting them with moving in and out.For Nook's Cranny, he wears a blue apron with his leaf symbol on it (in Animal Forest, it is the kanji 店 (ten?), meaning "shop"). The blue apron is inferred to be for modesty, referencing the legends of tanuki.

In Animal Forest e+, the player can wake up Tom Nook after hours by banging on the doors three times with the shovel. He will be in his pajamas and allow the player to shop, but he will move much slower. Not only this, anything the player sells to him will be lowered from its base price by 30%. Similarly, prices of items in the shop will inflate by 17%, and the player is only allowed to either sell or buy what is on display. The catalog and other options will not be available either. When the player first arrives in town, Tom Nook will greet them and introduce them to their new house. He will give a quote to them on the initial mortgage of the home. Tom will hire the player to work part-time at his shop to help pay off the loan. Eventually, he will run out of tasks for the player and will lay them off, letting them free to find other methods to make Bells, to pay off the rest of the debt. Following the job, the player can shop at Tom Nook's store and can sell items to him, for which he will pay for in full value.In Wild World, he will give out his picture if the player gives him the safe from the Golden Axe Trading Event.