Mai Tsuzuki, originally introduced as Misato Uehara, is a devoted fan of Blast and later becomes Nana Osaki's manager. An enthusiastic supporter of Blast since its early days, Misato loves Nana and has formed friendships with the band members. However, "Uehara Misato" is not her real name. Misato, also known as Mai, claims that a fortune teller advised her that using the name "Uehara Misato" would bring her closer to Nana, but she might have chosen it because it is the name of Nana's half-sister.
Mai eventually joins the staff at Gaia, Blast's record label. She learned about Nana and Blast after reading her grandfather's diary, which revealed that he and Nana's grandmother were once in a relationship. Recent chapters suggest that Mai may have a secret she wishes to keep hidden, especially since tabloids have discovered that Nana's father's surname could be "Tsuzuki," implying that she, like Uehara Misato, might be Nana's half-sister.
(Source: Wikia)
