[X] Tell her about the Yakuza problem, she might be able to help you, she is supposed to be a hero after all. Increased opinion from Sentai Elite, Sentai Black.
[x] Go home, your parents suspect you're a parahuman but you're sure they'd rather hear it from you than Kana, when the two month probationary period is over.
[X] The Yakuza were heavily dug into the government, maybe you could trust her but can you trust the remaining parts of the bureaucracy that made the Sentai function? Besides as a member of Japan's Parahuman programme the Yakuza would know better than to harass you anymore.