Mast Saibou

Оригінальне ім’я: マスト細胞

She is a white blood cell, specifically a Mast Cell (mastocyte or labrocyte). As a part of the immune system, she releases chemicals such as histamines and leukotrienes as a stimulus to excess production of IgE (Immunoglobulin E, an antibody produced by B Cells). (Source: Cells at Work Wiki)