Marika has been frail since her childhood, so she went to the mountain side with her father because of the clean environment. But due to her weak body, she stayed at the hospital and rarely went outside to play with her friends. And there she met Ichijou Raku, the two of them became friends and Raku used to visit her in the hospital room everyday and brought items for her from the forest. Marika used to call Raku, "Raku-kun" and Raku called her, "Mari", because Marika's father also called her with that name. Marika made a promise with Raku that they'll get married. So at the day of their parting, they took a photo together to remember their "important promise"