"Sato is the main character in ""Welcome to the NHK!"" He is a 22-year-old hikikomori, or shut-in, who struggles to leave his apartment and interact with other people. Sato is paranoid and often has delusions, believing that the NHK, or Japan's public broadcaster, is conspiring against him. He becomes friends with his neighbor, Misaki, who tries to help him overcome his social anxiety.

Misaki is a mysterious girl who claims to be able to cure Sato of his hikikomori status. She sets up a ""project"" to help Sato overcome his fears and become more socially active, but her true motivations are unclear. Misaki becomes Sato's confidante and helps him navigate his insecurities and mental health issues.

Yamazaki is Sato's friend from high school who is also a shut-in. He spends most of his time playing online games and is a self-proclaimed expert on anime and manga. Yamazaki becomes a mentor to Sato and helps him learn about creating visual novels, a type of video game. Yamazaki is also a bit of a slacker and often has trouble following through on his ambitions.

Kaoru is Sato's former classmate who becomes his roommate for a short time. She has a bubbly and outgoing personality, which contrasts with Sato's reserved and anxious demeanor. Kaoru tries to help Sato break out of his shell, but their differing personalities often clash.

Hitomi is a woman who works at the convenience store where Sato buys his groceries. She is friendly to Sato and even gives him free food sometimes. Hitomi has her own struggles, including a crippling gambling addiction that causes her to steal money from her workplace. Despite this, Sato sees her as a kind and supportive person who genuinely cares about him.

Overall, the characters in ""Welcome to the NHK!"" all struggle with their own mental health issues and social anxieties. They form a ragtag support group of sorts, each finding solace in each other's company and attempting to overcome their personal demons together."