Which are the most important music and rock festivals in Japan ?

Question:

like OZZFEST and rock and rio

Answer:

punkspring - early april every year (local and oversea punk, emo, ska bands)
fuji rock festival - late july every year (local and oversea rock bands)
rock in japan - early august every year (local rock bands)
summersonic - middle of august every year (local and oversea bands)
loudpark - middle october every year