A quick rundown of the characters:
Marii Buratei (蕪羅亭 魔梨威 Buratei Marii?) Voiced by: Ayane Sakura (Anime), Kana Asumi (CD) The substantial protagonist of the manga, who has long red hair. She behaves like Edokko and speaks in a masculine tone of Edo speech, but she is actually from Tokushima Prefecture. Despite her good looks, the way she talks and her flat chest tend to lead the others into suspecting her as a boy cross-dressing as a girl. She acts tsukkomi and often says "Don't ask a trifling question! (つまんねー事聞くなよ！ Tsuman'nē koto kiku na yo!?)". Her name is a pun on Bloody Mary.
Kigurumi Harōkitei (波浪浮亭 木胡桃 Harōkitei Kigurumi?) Voiced by: Kotori Koiwai (Anime), Erena Ono (CD) A girl with cream-coloured hair who is the youngest girl in the group. To match her childlike figure, she often pretends to be cute in front of others, but her internal dialogue shows her true thoughts to the audience; cynical and manipulative. Her name is a pun on Hello Kitty and kigurumi.
Tetora Bōhatei (防波亭 手寅 Bōhatei Tetora?) Voiced by: Nozomi Yamamoto (Anime), Ikumi Hayama (CD) A ponytailed girl with brown hair who is a lucky girl and leads a carefree life. She often leads the stories to other subjects. Kumeta introduces her as the true protagonist of the manga. Her name is a pun on bōhatei (防波堤?, "breakwater") and Tetrapod.
Gankyō Kūrubiyūtei (空琉美遊亭 丸京 Kūrubiyūtei Gankyō?) Voiced by: Yoshino Nanjō (Anime), Kana Hanazawa (CD) A girl with glasses and green hair who is a cool-headed and strong girl. She is a childhood friend of Tetora's. Her name is a pun on cool beauty and gankyō (眼鏡?, "glasses").
Kukuru Anrakutei (暗落亭 苦来 Anrakutei Kukuru?) Voiced by: Saori Gotō (Anime/CD) A girl with straight black hair who is very good at acting, but is an unlucky girl and is very emotionally unstable. Her name is a play on several words, all of which have to do with things that are very negative in nature. The pronunciation of her name refers to Anrakushi (安楽死?, "Euthanasia") and kukuru (括る?, "to hang"). Her name could also be read alternatively as kurakutei kurai, which is very similar to kurakute kurai (暗くて暗い?, lit. "dark dark"). Anrakutei also sounds similar to the word unlucky. Also, the kanji in her name minus the character Tei (亭?) could be read very literally, as falling into darkness and coming of anguish.
Mask (覆面 Fukumen?) Voiced by: Aoi Yūki A girl in a luchador wrestling mask who just happens to be in the scene at certain points.
Uzannu Uzattei (宇座亭 ウザンヌ Uzattei Uzannu?) Voiced by: Ryōko Shintani