From Wikipedia
Angerme (アンジュルム Anjurumu?), formerly S/mileage (スマイレージ Sumairēji?) is a Japanese idol girl group from Hello! Project. Originally started as an indies Hello Pro Egg unit in 2009, S/mileage was formed by four first generation members with the possibility that the line-up would be shuffled. The group graduated from Hello Pro Egg in 2010 and became full members of Hello! Project. The group changed their name in late 2014 to ANGERME to celebrate the third generation members and signify a turning point in the group's image.
In 2010, they won the Japan Record Award for Best New Artist. In 2011, five new girls were added to the group as part of the second generation, with two being former Egg members and three new girls, while also losing three members at the same time; three more members were added in 2014. As of November 2015, the group has nine members.
On November 11, 2015, the group announced that their fourth member auditions had concluded with Moe Kamikokuryou revealed as the new member. With Kanon Fukuda leaving on November 29, 2015, the group remained at nine girls. On December 20, 2015, it was announced that Meimi Tamura would leave Angerme and Hello! Project in spring 2016.