As announced last week, Stella Glow was showcased today during a SEGA livestream on NicoNico.
The gameplay footage showed what seemed to be a standard battle. At one point, the player activates the Song Magic of Sakuya (shown via a special cutscene), in order to power-up nearby allies. A bit later, another gameplay segment showed another Song Magic from Sakuya, which directly attacked the nearby enemies.
Here’s a recording of the SEGA livestream (the first gameplay segment starts at 11:46, the second one at 18:13):
Stella Glow (3DS) comes out on June 4th in Japan, and later this year in North America (courtesy of Atlus).