Maid is Ryuunosuke's AI program he wrote personally. Originally, Ryuunosuke designed Maid to filter and automatically reply to his cellphone messages and emails to save him time. However, Ryuunosuke keeps expanding Maid's AI ability. Maid is now capable of blocking and replying to a message or email by her own preference, using new words she has recently learned from other messages, emails, or the Internet in the reply.