Responsible Taihei has to deal with his lazy little sister, Umaru, who trashes his apartment and throws tantrums to get manga and junk food.

Summer vacation means hours at the arcade! Umaru instructs in the fine art of enjoying summer like a (lazy) pro. Later, Taihei endures another typical day at work.

In this last episode of the season, Umaru might have to reveal her secret when her separate circles of friends come together during a much anticipated trip to the beach!

Umaru Doma's life continues with an evening filled with video games... and no big brother in sight! Later, Umaru and her friends end up playing an intense game of soccer.

Alex interrupts Kirie and Umaru's afternoon to play a dating sim game. Kirie finds herself identifying with the main character. Later, Umaru discovers an addictive new game.

Taihei leaves for a business trip with his co-workers. While his boss Kanau thinks of a way to spend time with him, Taihei has his hands full with a vacation-happy stowaway.

It's the end of the year, and everyone is figuring out what Christmas gifts to get their loved ones. Can Umaru and the others find the perfect presents?