inspired more idol groups to appear, the majority of them being "local idols" who performed in specific rural communities. Several independent idol groups also crossed over into mainstream, such as Dempagumi.inc, Dorothy Little Happy, and Rev. from DVL, the latter of which gained mainstream popularity after a photo of then-member Kanna Hashimoto went viral. Since 2010, the biggest idol concert festival, Tokyo Idol Festival, has taken place. More than 200 idol groups and about 1500 idols performed, attracting more than 80,000 spectators in 2017. During 2014, about 486,000 people attended AKB48 and Momoiro Clover Z's live concerts, which was the highest record of all female musicians in Japan. Momoiro Clover Z has been ranked as the most popular female idol group from 2013 to 2017 according to surveys by The Nikkei, There were more than 10,000 teenage girls who performed as idols in Japan in 2017. In 2019, there were over 3,000 female idol groups. In the early 2010s, alternative idols, a sub-category of Japanese idol came about. Pioneered by Bis and Seiko Oomori, alternative idols are known for mixing idol pop music with heavier genres such as alternative rock and heavy metal. They have also been known for utilising shock value to gain public and media attention and making use of a darker image than that of the idol scene norm. From 2013 to 2018, boy band Arashi was ranked as the most popular artist overall in Japan according to Oricon polls of 20,000 people. Other male idols also found success as underground idols, as well as anime media mix projects and 2.5D musicals. Beginning in the mid-to-late 2010s, the Japanese idol industry crossed over with K-pop with the third Korean wave in Japan, which was sparked partially from positive reception of the Japanese members of the South Korean group Twice. In the years that followed, several Japanese and South Korean companies collaborated to form K-pop influenced groups for a global consumer base, such as Iz*One, JO1, and NiziU. Fan culture Fan activities Passionate male fans of idols are colloquially referred to as , derived from the word "." Beginning in the 1980s, they formed cheering groups known as to support idols at concerts and public appearances. During these events, the perform , an organized sequence of fan chants and dancing to show appreciation for the idols. Fan chants where an idol's name is called after each bar is