Rina Kawaei (L) and Anna Iriyama speak to the media as they are discharged from a hospital in Morioka, Iwate prefecture. REUTERS/Kyodo
The band, rated by Guinness as the world's biggest such group, was shaking hands with fans at a meet-and-greet function on Sunday when the man attacked them with a weapon described variously as a 50cm-long saw or a hatchet, media said.
Group members Rina Kawaei, 19, and Anna Iriyama, 18, received emergency surgery for cut and broken fingers, and Iriyama sustained cuts to her face.
Police have arrested a 24-year-old man in relation to the attack, BBC reports.
The number 48 in the band name reportedly refers to the original number of members in the group, although it has since expanded.
The current line-up on the group's website, spread over four main teams and other smaller ones, lists 140 names.
