[1] In 2011, Tashima took part in the 10th generation auditions for the idol group Morning Musume.

[4] She became soon a hot topic throughout Japan, after it was reported that AKB48 and HKT48 producer Yasushi Akimoto commented on her as being "the new Jurina Matsui",[5] a member who joined AKB48's sister group SKE48 at the age of 11 and was immediately appointed one of the front positions in the next AKB48 single and featured on its cover art.

Another surprise came when Tashima, in spite of officially being a trainee member, was appointed the central position in her band's first original song "Hatsukoi Butterfly", to be released as a B-side on the 29th single by AKB48.

[6][7] In HKT48's second single "Melon Juice", Meru Tashima was again featured in a central position.

She played the role of Yoshio Yamamori, based on Nobuo Kaneko's original portrayal.