Fudajo! ~Otome Shoukan Datsui Taisen~ - Vol. 4 Ch. 40 - Special Ability - Union!!

[MangaDex]

 

[redscizor]

Fusion maybe? Or better Sync with the warrior?

 

[Dionaea]

The amnesia shenanigans are a bit concerning. It could mean anything from Poppo being an AU version of Machida to the event being an annual happening

 

[beep_repair]

The amnesia shenanigans are a bit concerning. It could mean anything from Poppo being an AU version of Machida to the event being an annual happening

True, though I suspect the main thrust will be that Machida has a complicated past he doesn't remember

 

[GnatteringYawn]

The amnesia shenanigans are a bit concerning. It could mean anything from Poppo being an AU version of Machida to the event being an annual happening

One thing I'm pretty sure it connects to is that dream Asahi had back in volume 3, where she saw Ashura crying and apologizing. Whatever it is that Asahi and Machida forgot, I don't think they were having a very good time.