To be fair, his friends can't do shit and would probably just get destroyed in seconds, especially if they are stupid enough to climb that entire pagoda.
The only ones that can likely help a bit is Yuki, who's an archer, and Nishiyama, who's a (bro) bomber who cooks.
Yuki can attack Miyabi from there and Nishiyama can join her for bomb arrows or cooking to make him hungry or distracted, or maybe even to give Akira more motivation, as his food aparently heal broken bones (I wouldn't put it pass Higanjima).