"Party x Party" is an original song by teamOS. It tells the story of a rookie (Miku) who does not wish to be alone one night and decides to go on a quest to "have the party of her dreams". On her path she encounters a gunner (Len) and a bard (Rin). They head together to the NicoNico Pub, where they meet the bartender (MEIKO), the merchant (KAITO), and the dancer (Luka). The 6 of them decide to head out in the morning after a chaotic night to embark on their own quests. They hit numerous bumps in the road, but the group travels on, determined to finish their quest. The party happens upon the final boss' chamber, just to find out that the rookie was the Dark Lord all along. However, the 6 of them put aside alignment differences to throw the ultimate party.
The title, Party x Party, is most likely a pun on meaning: the party, or group of fighters, go forth on a quest for the ultimate party. This can further be supported by the fact that the music video's graphics are akin to the interface of a role-playing game (RPG). The song was released as a theme song for Nico Nico Cho Party 3.
IMPORTANT NOTE: Some lyrics may be attributed to the wrong singer, as there is no official log of who sings what, specially the parts with black lyrics without color squares, as they mean that some combination of singers is singing that part.
Singer + Color
tsukiakari ga ayashiku sasou yoru
konna yoru ni ohitoribocchi wa iya!
yume no you ni tanoshii paatii ga shitai no
omoitatta ga kichijitsu! sassoku tabi ni demashou ♪