According to an announcement on Hello! Project's official website, Morning Musume members Mitsui Aika and Sayashi Riho will be withdrawing from their current concert tour, "Hello! Project 2011 SUMMER".
Because of her previous ankle fracture, Mitsui is being advised by a doctor to rest for approximately eight weeks. Sayashi is currently at home for sciatica (pain, numbness or weakness in the leg caused by the injury/compression of the sciatic nerve), and will not return for about six weeks.
Mitsui developed a stress fracture in her ankle last May while on tour with Morning Musume, but decided to continue working while treating her ankle. Although the idol sat for many of her performances, it appears as if the condition was not entirely healed, so doctors are requiring that she take a break.
Sayashi brought attention to pain in her lower back after their July 16th performance in Nagoya, and has since been surveyed by doctors to see how her condition developed. As a result of her medical examination on the 28th, however, the young idol was diagnosed with sciatica and assigned a required six-week rest to recover.
Both girls will miss out on the rest of the Hello! Project summer tour this year.