The Strong Katana is a rare melee Weapon that can be found when scavenging the Museum location.
It is almost functionally identitcal to the Otaku Katana but can not break. The cooldown is also 0.2 seconds longer, meaning it is less viable for weaker party members.
The Strong Katana however scales in power with the wielder's Strength / Fitness.
The trait "Anime Fan" gives the character the Strong Katana from the start of the game