Intermediate Level or Level 3 and 2 of Japanese Language Proficiency Test (JLPT) have about 5000 to 10,000 characters. The grammar is even less controlled than Level 3 plus Kanji (Chinese characters) have no ふりがな reading printed next to them.
Grammar / 文法
causative form, causative passive form, ～そう（information）, ～らしい, ～はず, ～もの, ～ようにする/なる, ～ことにする/なる, etc.
