Bokutachi Otoko no Ko (KIRISHIMA Ai)

From MangaHelpers:
Sakurai Seri wants to be an idol, but he’s so nervous that he seems to only meet with failure. Then, one day, he and two other boys are chosen to debut as members of a new idol group, “Otoko no Ko.” The other two boys are the cool, serious “Ren” and the enthusiastic, cute “Tama.” The only catch is that they plan to be a male idol group that dresses as girls. This may be Seri’s big chance, but he never imagined himself as a female idol.