Second daughter of the Tsukishima family in 5th grade in Part One. Through their childhood Wakaba is constantly with K. She constantly talks about their future together even giving him a schedule of suggested future birthday gifts that includes an engagement ring for her 20th birthday. She frequently kisses K which annoys their mutual friend Akaishi who has a secret crush on her. For several birthdays in a row Wakaba gives K alarm clocks because he has a hard time waking up in the morning. Her name means young leaf.