BENI :D
She is awesome! My favorite Japanese singer of all time
Here are some of my favorite songs (to be quite honest, I don't dislike any song from her)
Mounidoto, Kiss kiss kiss, 2FACE, Yura yura, Gimme Gimme, Darlin', Crazy Girl, Sign, Bye bye, Our Sky, One in a million, Kira kira, Break the Rules, Lovers Again, Eien, Ti Amo, Nice & Slow, A million Jewels, Memory, Stay, Yes or No, Beautiful World, Secret, Superstar, He is Mine, Heartbreaker and the list goes on and on XD

I really hope you enjoy some of them :D

Ummm.... Lol, I at this, but I will give it a shot!! ^^

MBLAQ- Mona Lisa
hey! say! jump - mayonaka no shadow boy

Lol, if I think of more I will tell!

Hmmm . . . . I'll just recommend some awesome Suju songs that I like:
Suju-T - Rokkugo (Heenim . . .)
Suju - Wonder Boy
Infinite - I don't know (kind of rockish ^^)
Hangeng - Still at your side
B1A4 - Remember
FT Island - Hello Hello, Like the Birds, I Hope, Love Love Love
JYJ - Get Out
MBLAQ - Oh Yeah, Y, This is War, Stay
Wonder Boyz - Tarzan (I'm gonna go be hipster and say that I had this on my phone before EYK even heard it ^^)
B.A.P - What the hell?, Fight for freedom, Punch
MBLAQ - Mona Lisa Jpn Ver. (I usually hate translated songs, but this is so good :O)

I have so many types of songs that I'm in love with, if you want something other than that :D

If you haven't listened to Jaejoong's Mine, omfg listen to it. It's ing fantastic, fabulous, Korean rock. http://youtu.be/GYgTJ9D4Rgg

J-Pop:

YUI - Hello
YUI - Life
YUI - Again
YUI - Rolling Star

^^[You can't go wrong with YUI (AND she has a VEVO! Search YUIVEVO on YouTube)]

Ikimono Gakari - Bluebird
Ikimono Gakari - Sakura
Ikimono Gakari - Hotaru no Hikari
Ikimono Gakari - Hanabi

^^(Seriously, like ALL their songs are good, no AMAZING!)

Utada Hikaru - Sakura Drops
Utada Hikaru - Passion
Utada Hikaru - Come Back To Me

^^(The Queen of Pop in Asia, you can NEVER go wrong with her, her voice is divine and she speaks fluent English because she was born in New York City, she's the best! Her official YouTube channel is called HIKKI. Look her up you will NEVER regret)

Rie Fu - Life is Like a Boat
Rie Fu - For You

^^(Her voice is amazing, so soothing and calm... and she can speak English fluently which she does in most of her songs.)

E-Girls - One Two Three
E-Girls - Celebration
E-Girls - Follow Me

FLOWER - Sakura Regret
FLOWER - Bright
FLOWER - Still
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J-Rock:

One Ok Rock - The Beginning
FLOW - Colors
Stereopony - Stand By Me
Stereopony - Hitohira no Hanabira
Stereopony - Tsukiakari no Michishirube
SCANDAL - Shoujo S
SCANDAL - Shunkan Sentimental
SCANDAL - Harukaze
SCANDAL - Sakura Goodbye
SCANDAL - Doll
High and Mighty Color - Ichirin no Hana
High and Mighty Color - Hot Limit
High and Mighty Color - Amazing
Asian Kung-Fu Generation - After Dark
Asian Kung-Fu Generation - Rewrite
UVERworld - Core Pride
UVERworld - Chance
Aqua Timez - Alones
Aqua Timez - Velonica

^^(You seriosly can't go wrong with any of those songs, they're all great by equally great bands. Some songs may be harder to find than others but just copy paste all of them onto YouTube, if there are no results search them on Google.)
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If you want more suggestions just ask me. You're welcome. Please take the time to listen to each and every one of those songs. ^____^

You could do Clara's Dream/Dream Of Clara by Orange Caramel(technically it's Lizzy's solo off their album) It's not rock but it sounds traditional somehow XD and French influences with a bit of IU's song in it ( my opinion though)

Caffe Latte and Officially Missing you by Geeks :D

Orange caramel Shanghai Romance(:

I'm not really sure. But I know BAP's No Mercy has traditional Korean music in it.

Orz.... I dunn know more .... but have you listened to Roy Kim?