You should equip Yukari hat to get effect.

Hat Upgrade Lev.1(default)
- Multiply power regen by x1.2

Hat Upgrade Lev.2
- Bonus sight range 1
- Hat bonus graze chance 10%
- Damage Reduction 20%

Hat Upgrade Lev.3
- Waterproof
- Max power +20
- Hat bonus graze chance 20%
- Multiply power regen by x1.5
- Damage Reduction 40%

Hat Upgrade Lev.4
- Fire Resist
- Posion Resist
- Bonus speed 1
- Max power + 50
- Bonus sight range 2
- Hat bonus graze chance 30%
- Multiply power regen by x1.7
- Damage Reduction 60%

Hat Upgrade Lev.5
- Teleportation (press T to teleport, cost 20 power)
- Max power + 100
- Hat bonus graze chance 40%
- Multiply power regen by x2.5
- Damage Reduction 80%