you use the mortar at the great bridge to fix it
you use it on the bridge
On the bridge
You use the mortar to put the blocks together.
there isn't a special time you need it, you just use it to fix the pridge.
you have to get cement to fix the bridge then you fix the bridge ITS EASY!
You use the Mortar that u find near the house all the way to the left
you go to a unfinished wall and click use =)
you use the mortar for the red bridge so the wrestlers could go to the match
The bag of mortar is found near the lake house to the left of West Edo. Use it to repair the weakened bridge. Talk to the old man on the bridge and then fit the pieces together to reinforce the stone blocks.
you have to use it for the Kappa
You use a ninja star.
If I remember correctly, you must go to the hut that Basho lives in (found if you keep on going left after the market). There will be a short bridge consisting of three rocks and on the very first rock you see, there will be a bag of mortar. Once you click on it (or rather land on it), it will be put into your backpack. Use the mortar to fix the bridge.