The otaku katana can potentially attack up to 3 targets for twice the damage of a Baseball Bat. The quick cooldown makes it a good weapon for dispatching zombies.
The key weakness is the 5% break chance. This is higher than average for melee weapons and makes the katana potentially a liability if it's the only weapon the character has.
The Otaku Katana is not to be mistaken for the Strong Katana which has the same model but is significantly better.