The eldest of four siblings. Ichika, who helped her parents who work together and did housework, is a dispatch staff of a housekeeping service by making use of her special skills. Tamawa is the first customer to appoint Ichika, who has just joined the company, and has been a regular customer since then. However, the purpose of her ball ring is not housework but her body. "Is she your next target?" The person who came disguised as a visitor was Oshima, a bondage maniac.