Black Sheep Hit: "Hashire!" (the B-Side of "Kaitou Shojo") ranked first in their song popularity polls by fans in 2012. "DNA Rhapsody" (the B-Side of "Mouretsu") did the same in 2013.
Meaningful Release Date: "Rodo Sanka", or "Labor Hymn", a single about working labor, is released in November 23, which is the Labor Thanksgiving Day in Japan.
Their second album 5th Dimension is released in the day Akari graduated.
The Merch: Aside for standard idol merchandises (photos, bromides, photobooks, t-shirts and so on), they're the only Idol Group that saw an exclusive and limited releases action figures release by Bandai (yes, that Bandai) in Chibi-Arts line back then when they're not so famous. There's also Momoclo's Bento.
They Also Did: They voiced Beelzebub in Square Enix's fantasy rhythm action game Demons' Score, with her theme being composed by Hyadain.