Jelaskan "Tsuyoi Hana" dari So Long!

Kenkyūsei: Moe Aigasa, Saho Iwatate, Natsuki Uchiyama, Ayano Umeta, Miyuu Omori, Ayaka Okada, Nana Okada, Saki Kitazawa, Mako Kojima, Yukari Sasaki, Ayana Shinozaki, Yurina Takashima, Miki Nishino, Hikari Hashimoto, Rina Hirata, Mitsuki Maeda, Yuiri Murayama, Shinobu Mogi