This is another band that may interest you, they can be considered in a similar vein tonally to ONE OK ROCK. Though at times their energy in songs has a higher, and somewhat harder energy to it, their guitar work is some of the best I have heard in recent memory. That is not to say that they do not do well with a more somber musical style.
They of course have done music for anime, and I discovered them due to intro to the anime Noragami "Goya No Machiawase" (午夜の待ち合わせ) or roughly 'Meeting of the Night'. It starts out strong, and carries the energy throughout the song, without feeling strained. My favorite song on the Album "Masked Monkey Awakening" has to be the first song "Saru wa ki kara doko e ochiru" (猿は木から何処へ落ちる) the best I could find is 'The monkey from the wood falls to somewhere', regardless of the name, the song is once again an energetic romp from beginning to end.
The band is made up of Shun Taro (Vocals&Guitar), Narumi (Vocals&Guitar), Tasoko (Guitar), Makoto (Bass), and Yuki (Drums). They are a dual vocal 5 piece band with 3 guitars, bass and drums, and the sound is nicely textured with the three guitarists working well to compliment each other to make a crisp complex sound. To date a good amount of LP and EP have released, and appears they are currently on tour in Japan. If you are interested in finding out more about them I will once again leave the pertinent info at the bottom. If there is anything you want to add or that I missed leave it in the comments, thanks for reading!
Official Site: http://www.hellosleepwalkers.com/
Official Youtube: https://www.youtube.com/playlist?list=PLE63EF2D087D21BF1
Twitter (Band): https://twitter.com/hsw_japan
Fan Newsletter: https://fofa.jp/asketch/a.p/106/