I think this is a reference to the IOSYS remix song "Tsukiyo Wo Kakusanai Teido No Nouryoku?" from their 'Touhou Tsukitoro' album.
The song's title is a kanji pun; squeeze the characters for "moon" and "night" together, and you get the 'waki' (armpit) kanji. It goes on singing about how we all love Reimu and her armpit-flashing ways, but she sucks in the games, and can't even come in first place in the character popularity polls on 2ch.
I -
love -
you -Armpit Shrine Priestess
Re - i - mu