Yui is entrusted with his relative, Ko○mo, Chinta, by the president of a business partner to whom she owes a debt of gratitude. However, this Chinta is an incredibly precocious Yui! Although Yui usually behaves arrogantly as a president, she is taken aback by Ko○mo's pranks! When he spoils her and they take a bath together, she is shown an erect penis that rivals that of an adult, and Yui is not completely Yui. Chinta, who is still excited by living with an adult woman, begs for sexual relief in the president's office without telling the other employees! The two of them escalate their actions in any direction, and Yui, who is actually frustrated, gradually becomes addicted to the penis...