On a related note, the series she's in should probably be called "hitsugi_no_chaika", not hitsugi-hime_no_chaika. Japanese Wikipedia gives this reading: (『棺姫のチャイカ』（ひつぎのチャイカ）). I also found this blog post that says "棺姫でひつぎひめではなくひつぎと読みます。" ("棺姫 isn't Hitsugihime, it's read Hitsugi.") And this one that says "ちなみにタイトルは「ひつぎひめのチャイカ」ではなく「ひつぎのチャイカ」と読みます。" ("By the way, the title isn't read 'Hitsugihime no Chaika', it's 'Hitsugi no Chaika'.") Additionally, various online stores like ehon, 7netshopping, toranoana, and DMM list it as "棺姫（ひつぎ）のチャイカ".