Girls that got their last 4* less than a month ago:

• Rin Rin

• Yukinya

• Chisato

• Maya

• Reona

• Masuki

• Rei

Girls that got their last 4* 1-2 months ago:

• Hina

• Tae

• Kaoru

• Sayo

• Ako

• Kokoro

• Tsugu

• Moca

Girls that got their last 4* 2-3 months ago:

• Kanon

• Misaki

• Tsukushi

• Rui

• Arisa

• Kasumi

Girls that got their last 4* 3-4 months ago:

• Saaya

• Eve

• Chiyu

• Rokka

• Lisa

Girls that got their last 4* 4-5 months ago

• Himari

• Nanami

Girls that got their last 4* 5-6 months ago:

• Aya

• Touko

• Mashiro

• Hagumi

Girls that got their last 4* 6-7 months ago:

• Ran

• Rimi

• Tomoe

So the next event (aka Halloween) should be mixed, since we have a cover song (Setsuna Trip) that's yet to be in the game, and that we haven't had a mixed Halloween event for 3 years

Rimi is def a Halloween 4*, since the cover is a Popipa cover

Tomoe MAY be the other 4*, but I'm placing my best bet on a DF V2 card since she needs another powerful 4*, and the halloween event is def not powerful

Ran won't be the other 4* nor a DF V2 card since she's getting one on Afterglow's 3rd Band Story, so I'm placing all my bets on Hagumi being a Halloween 4*

There's still the other DF V2 card, tho. Besides Afterglow, Popipa and Pasupare are the bands w/ the least recent DF V2 card, and since Aya has the least recent 4* of all the Popipa (besides Rimi) and Pasu members, she should be one