I read a lot of Japanese fans' discussions in 2005-2020, including 2CH and personal blogs.
Because Juka has much groupie at that time that it even affected MDM, Japanese girls hated Juka very much. They even scolded mana that Juka be MdM‘s vocal was the stupidest thing in his career
This is one of them:
http://xxxasukaxxx.fc2web.com/live/repo/2013/0320.html
The girl wrote her 10th anniversary repo
最後に皆出てきて折角だから一言ずつMana様にメッセージをってことで
各メンバーそれぞれ挨拶的なものをしたんだけど
Jukaが「実は正直なところ、Mana様とぶつかって辞めました」とか余計なことを…。
お前がファン食い激しくてクビになったの皆知ってるよ…。
魚釣りしてる時に「ライヴ出てくれない?」って電話かかってきて
1分くらい名乗らないけど聞き覚えある声で~とか話してた。
今は確執もなく、また20年祝いの時に出たいですって言ってた。
お前がファン食い激しくてクビになったの皆知ってるよ…——Everyone knows that he has too much groupie LOL

Juka was not friendly to mana when he left MDM(I'm sorry my English is not good. I can't write down the discussion of Japanese fans in detail in English,he did several things to make Japanese fans angry

)
After several years, he seems to find that he still misses MDM
He got an invitation call from Mana while he was fishing
So he went to the 10th Anniversary Show
As in particular groupies, or...? Because Juka's side of the story (via Instagram) was that his fanbase in general was much smaller than what he wanted out of fame. Basically he wanted something more like Gackt's level of success but Juka stated he couldn't even afford to eat rice sometimes from the little money he was earning; it just wasn't worth it. Also, it could be true that he didn't get along with Mana, but he still wears his Moi dix Mois hoodies when he goes on fishing trips, so I'd like to think he can't dislike Mana *that* much anymore or else why even show off?