Shiggy Jr. is a band that formed out of Aoyama Gakuin University in Japan, in December 2012. Currently comprised of members Tomoko Ikeda (Ikemoko) as main vocalist, Shigeyuki Harada (Shige) as guitarist and vocals, Natsuhiko Mori (Mori-san) on bass and Kazuma Moroishi (Moroishi) on drums.

The band formed when Shige, who would sing, play guitar and compose his own music, wanted a female singer for one of his songs, whereupon an acquaintance by the name of Rika Sunea recommended Tomoko Ikeda from her circle, the Aoyama Music Society, suggesting she would fit the feeling he wanted for the music. Tomoko would become the new main vocalist and Rika would also go on to join the group as Keyboardist, along with two other members from the same circle, Fijii as drummer and Gen as bassist.

In November 2013 the band released their first EP ''Shiggy Jr. is not a child.''

In February 2014, drummer Fijii and bassist Gen left, followed by keyboardist Rika Sunea in March. Mori-san and Moroishi were brought in as replacements, as bassist and drummer respectively.

In May 2017 they signed to the Victor Entertainment label.