Let's start jamming Atarashii Gakko - Rakuen Nite Watashi Jigoku chords, Practice these chords sequence - Fm, Db, Fm, Db and Ab. I suggest starting at a calm pace of 64 BPM, and as you gain confidence, approach the song's BPM of 128. Align the capo with your vocal depth and chord choice, bearing in mind the song's original key: Ab Major.