Here's a bunch for ya. I loooooooove me some J-punk lol.
New Rote’ka (ニューロティカ)
After 8 years, still my favorite Japanese punk band. Active since 1984. They have a great sense of humor, they kickass, and the singer is a clown! Lol. I actually talked to a few of the band members over the years as well. Ridiculously nice guys.
COBRA
Gods of the Japanese rowdy “oi!” subgenre, COBRA have been punk icons since its formation in 1983. They even had some very unlikely commercial success during the early 1990’s. They’ve been largely on-and-off in terms of activities since 2015 though.
STANCE PUNKS
A bit of a younger band that formed in 1998. Although largely known overseas for doing a song for Soul Eater (which, like many overseas people, is the first time I heard them lol), these guys had some really great stuff. Totally full of the original punk spirit as this video will show ya!
BOMB FACTORY
Around since 1991, unlike most of the other bands on here, it took BOMB FACTORY quite a while to attract a following. About 7 years, to be exact lol. But they’ve since developed a strong underground cult following for their unique blend of punk and harder, semi nu metal elements.
locofrank
Ahh man, these guys are great! Around since 1998, these guys took off like wildfire beginning in the early 2000's, reaching their commercial peak in 2006. They're very melodic, kinda poppy but not really. Pretty much the picture perfect definition of melodic hardcore, since I can't think of any other way to describe them lol.
KIkeiji (奇形児)
These guys... are fuckin' crazy lol. One of the unsung heroes in Japanese noise punk, Kikeiji, which translates loosely to "deformed child", were one of the most unforgiving and brutal sounding bands in the 80s Japanese punk underground. For that reason alone, they attracted a small cult following during their original run from 1982 through 1985. Surprisingly reuniting in 2008, Kikeiji have since been rocking and "wtf"-ing audiences across the underground, and remain certainly one of the most memorable bands to emerge from the 80s Japanese hardcore underground.
FULLTRAP
FULLTRAP are a band that blew up overnight, probably the quickest rising band in terms of popularity on this list. Around primarily from 1998 through 2003, their sound was a blistering blend of hardcore punk and thrash. The guys have been semi-active once more as of 2014, however, playing one live that year, and another live in June. Here's hoping for some more shows, these guys slayed.
THE ERECTIONS
The youngest band on here forming in 2002, it took these guys 9 FUCKIN YEARS to release any material. But it was worth it! These guys have the old school punk image and sound, although the comment section reminds me why I don't associate with "I'm a true punk" assholes. Great band though!
SA
Originally around from 1984 through 1987, SA (short for Samurai Attack) reunited in 1999. and released two of the greatest punk albums of the early 2000's: "You Must Stand Up My Comrades" and "GREAT OPERATION". They used to be AMAZIIIIIIIING. However, starting around the 2010's, they started becoming... a different kinda band. One that is much more reliant on classic rock'n'roll/rockabilly kinda stuff, which I hate. So while they're still around today, I do not recommend their newer stuff at all. Rather I recommend this. Slamminggggggg.
Lolita No. 18 (ロリータ18号)
Wow, I'm surprised no one mentioned them yet. Huh... well, around since 1989, Lolita No. 18 are arguably the first all-female punk band from Japan to really blow up outside of Japan. They toured around the globe, and went on to work with punk icons like Toy Dolls and Joey Ramone, who was reportedly a big fan of theirs, and who produced their 1997 album "Fubo NY (父母NY)". They're also a pretty weird band, with a core of the band during their heyday adopting cartoony personas, and the vocals themselves sounding very cartoony. Legends! Enapou~ ❤️ lol.
NICKEY & THE WARRIORS
Primarily a punk band, NICKEY & THE WARRIORS went through a weird post-punk/new wave sound during 1987, which was... meh. Their punk stuff though is great. Originally known as WARRIORS, the members changed its name and entire style in 1986 to NICKEY & THE WARRIORS, centered around charismatic frontwoman NICKEY. They were originally only around for around a year, but reunited from 1990 through 1993, before reuniting for good in 2002. They're known for being one of the first female-fronted punk bands in Japan, and remain total icons today.
GARLIC BOYS
Around non-stop since from their formation in 1985 until their short split in 2014 (reuniting in 2017), GARLIC BOYS are up there with New Rote'ka with longevity in terms of punk bands, and are widely regarded as one of the most iconic and influential bands in the underground Japanese punk universe.
GOOD 4 NOTHING
Around since 1998, GOOD 4 NOTHING are unapologetically pop punky, and unabashedly western influenced, sounding similar to bands like blink-182 and New Found Glory. I'm a bit come-and-go with them, but they've got some pretty great stuff.
https://www.youtube.com/watch?v=OhqrYpExQ2A (not embeddable. Goddamn Universal lol)
KING BROTHERS
Around since 1997, although on a semi-hiatus from 2013 through 2017, KING BROTHERS are known to be one of the most destructive and downright chaotic bands to see live, and are probably the finest band in the subgenre of blues punk. Very loud, very over the top... very badass lol.
ABNORMALS
Last but not least, ABNORMALS is a band that needs much, much, MUUUUUCH more love outside of Japan. Formed in 1988, they're another band that had a slow start, releasing their first mini-album in 1995, before blowing up like dynamite by the turn of the millennium in the underground. They're like the Japanese Danzig and are very gloomy, yet very heavy-hitting. Sorta like a horror punk-hard rock hybrid. Amaaaaaazing stuff.