Assassin’s Creed Shadows does not shy away from including missions for either Naoe or Yasuke that take them all across Japan outside of the main campaign. The Kamon Crests are a series of 9 samurai clan crests that Yasuke is tasked with collecting.
Getting to them all can be daunting when you consider Ubisoft’s massive open world in Shadows. However, our guide to their locations can make it much easier to find them all.
How to Start “A Collection of Crests” in Assassin’s Creed Shadows

The first thing you will need to do is unlock Yasuke as a second protagonist. This means that you will have to progress the main story up until the end of the “Belly of the Beast” mission. Once you have Yasuke on your side, it’s time to meet the character who tasks you with retrieving the Crests.
The man you’re looking for is Ota Gyuichi, who resides in Southern Kyoto, found in the Yamishiro area. It could make sense to grab a nearby viewpoint or Kakurega while you’re there to unlock a fast-travel point back to the region. Head to the Honnoji Temple’s southeastern corner to easily locate Gyichi with the Observe mechanic.
Talking to him opens up the quest, and the Kamon Crests are now waiting to be picked up.
Where to Find All the Kamon Crests

Firstly, each of the nine Kamon crests you are looking for is marked by a flag symbol on the map. However, you will need to zoom in to the maximum to see them, like with Jizo Shrines, and their low numbers, these can be hard to track down.
Secondly, most of the Crests are hidden behind large, movable crates, meaning that Naoe cannot get to them. While we did try and find ways around the obstacles with Naoe, there were simply no openings or crawl spaces to take advantage of. Yasuke should be your choice of Assassin to take along for this one.
With that out of the way, it’s time to take a look at where you can find each Kamon Crest:
Akiyama Clan Kamon

It is found in eastern Yamato near the Hidden River sub-region. It is on top of a pagoda at Uda Mutsuyama Castle with a viewpoint, making it hard to miss. You could scale the viewpoint with Naoe and switch to Yasuke at the top to have an easier time getting to it.
Akechi Clan Kamon

It is at Sakomoto Castle, in a building next to the main tower. You could use the nearby viewpoint to make switching between Naoe and Yasuke a breeze. Just make sure to stay higher up, as it can be difficult to climb back up with Yasuke, and you cannot switch characters in restricted areas.
Bessho Clan Kamon

This one’s at Miki Castle in Harima, northwest of Amagasaki. The Kamon is in the guard tower. Taking Yasuke along is a good choice for this castle, as you will have quite a few enemies between you and the Kamon.
Ikko Ikki Clan Kamon

The Kamon is at the southwestern border of Izumu Setsu and Kii, at the Negoroji Kunren-ba Temple. You can find it in the guard tower behind a movable crate that Yasuke can easily handle.
Hashiba Clan Kamon

It is at Hiraiyama Fort in Harima, northeast of the main city. As always, using the Fort’s viewpoint to switch between Naoe and Yasuka as needed is a good idea, considering a significant enemy presence in the area.
Niwa Clan Kamon

It can be found in Tsuruga Castle, in the southeast area of Sotomo Gate in Wakasa. Once inside, look for a small building with a movable object at the foot of the main tower hiding the Crest inside.
Shibata Clan Kamon

This one’s safely tucked away one floor above the Legendary Chest in Genbao Fort in Mount Uchinakao, Wakasa. The viewpoint right above is very useful in getting to it quickly.
Oda Clan Kamon

This can be a tough one to get. It’s in the castle at the northwestern part of the Fukishima Ruins in Osaka, Izumi Setsu. It’s one of the earliest Crests you can collect, although you will need Yasuke to move the giant crate that’s blocking access to it.
Tsutsui Clan Kamon

The final Kamon is in Koriyama Castle at Yamato, between the Nara Heartlands and Lost Hills sub-regions. It’s on one of the floors in the Castle, which can be easily accessed from the viewpoint above.
With all of the Kamon Crests in hand, travelling back to Gyuichi to hand them over rewards you with an excellent Legendary Bow and Engraving for Yasuke, and 1,100 XP, which could be very useful when you are trying to get a viable build for Naoe or Yasuke going in the early stages of the game.