At the highest hill northwest of the Chasuriyama region in Tamba, you can find the Chasuriyama Kofun. If you’re planning on unlocking all allies in Assassin’s Creed Shadows, you won’t miss this one, since you must complete it during Yagoro’s quest.

To get inside the Makino Kurumazuka Kofun in AC Shadows, you need to come back as Yasuke, as only he has the ability to open the Kofun and get inside. Once you do so, you need to do the following: Have Yasuke pick up one of the red explosive pots. Carry it down the Kofun steps to the rubble.

The Old Kofun in Assassin's Creed Shadows is located in the Izumi Settsu region and boasts prominent rewards to collect.