1️⃣ Ganbaru! is NOT meant to be your primary resource material. In fact, it is meant to be used as a reviewer.
2️⃣ Ganbaru! does NOT use romaji. After all, there is no romaji in the JLPT.
3️⃣ Ganbaru! does NOT have N4 to N1 yet. So all you will get is N5 for now.