Kanjani no Shiwake Eight is a variety TV program that has featured arcade Taiko being played on-stage several times, and they have 10 J-Pop songs in a special Sorairo build that is only playable at the TV Asahi station! All of them are accumulated over the course of the show for the past few months.
There are ten videos so watch at your own time. The first one is shown above, T.W.L by the band Kanjani Eight, which is a cool 6* Oni (dificulty 3/4/6/6)
Here are the rest of the songs. Remember that they're technically authentic, just not open to the public machines in the arcade, like the three NicoNico Conference exclusive songs. Some of the artist names are missing so assistance would be great!
- Zurui Onna (ズルい女) - Sharam-Q, 3*, 4*, 5*, 6*
- HONEY - ???, 3*, 4*, 5*, 6*
- Aoppana (あおっぱな) - Kanjani Eight (glitch; all are displayed as 1*)
- Aruite Ikou (歩いていこう) - JUN SKY WALKER(S), 3*, 4*, 5*, 6* (not to be confused with Ikimono Gakari's song of the same name)
- survival dAnce ~no no cry more~ - TRF, 3*, 4*, 5*, 6*
- ultra soul - B'z, 3*, 4*, 5*, 6*
- Naniwa Iroha Bushi (浪花いろは節) - Kanjani Eight, ?, ?, 6*, 6* (Taikojiro reproduced)
- Chiisana Koi no Uta (小さな恋のうた) - MONGOL800, ?, ?, 7*, 6* (Taikojiro reproduced)
- Yuuyaku (誘惑) - Kanjani Eight, ?, ?, 5*, 6* (Taikojiro reproduced)
Credits to tetsutaro for the find!