Kenji, the second son of three brothers, was always seen by his mother, Iroha, as the child who required the least effort. However, everything changed one spring: his older brother started working and moved out, his younger brother entered a boarding school, and his father was sent away on a business assignment. Suddenly, only Kenji and Iroha were left living together. In the silence of their once-bustling house, Iroha is overcome by a sense of loss. Feeling frustrated and empty that his mother only ever focused on his siblings, Kenji decides to seize this opportunity to monopolize her affection for himself...