It's been something that's been bugging me for a while, why are there grenades in his Inventory ? I haven't found a use for them even after all the years of owning the game. I don't know if anyone else has notice them or just me but some light shed on the situation would be greatly appreciated

I think you're confusing grenades with the dynamite. You blow up the tunnel that Mina Onda is in. If you'd completed all mission objectives you would know that.

Actually, I've finished the game alot of times So I already knew about the dynamite in the wall

This.

That's what I'm talking about.

Well actually I think you'll find that is the explosive you use to blow up the tunnel. It's the only explosive in the game. I always assumed you picked up dynamite in the well.

Just redid the level again, the explosive that's used to blow up the tunnel is already in the wall ready to be connected up so you can blow it. Seems the nades are just for show ?

I thought that the grenades were used to blow up the dam and cause mass flooding around Hanuda in the movie scenes after Kei's last mission?

Maybe not, because somehow I don't think that grenades are enough to destroy thick concrete or something like that...

Yep, they were still there and sadly you can't equip them

I have no idea what they are for. Maybe 'Kei' likes carrying them to feel badass.