KANJANI8 (関ジャニ∞) recently revealed their 31st single Gamushara Koshinkyoku (がむしゃら行進曲) with tie-up as the theme song for NTV drama Jigoku Sensei Nu~be~ staring member Maruyama Ryuhei. The single is also the 3rd and final of their 10th anniversary releases. Single Gamushara Koshinkyoku comes on two editions releasing...