Unlock the following bonuses from Bob B at Naomi's Place by completing the corresponding challenges:

BONUS - CHALLENGE
Amon's Sunglasses - Defeat Amon.
Beads of Good Fortune - Complete Challenge Lockers (unlock all one hundred lockers, under and above ground).
Dragon Sarashi - Complete Challenge Hostess Maker (complete all hostess side missions for Hostess Maker).
Dragon Shirt - Complete Challenge No.1 Hostess Maker (train all hostesses to reach the number one spot).
Ebisu Socks - Complete Challenge IF7-R (defeat all enemies).
Golden Gun - Complete Challenge Mini-games (complete each mini-game).
Hercules Gauntlet - Complete Challenge Modding (make all weapons and gear for both Works Kamiyama shops).
Journal fo a Rare Sign Maniac - Complete Challenge Fighter Maker (all apprentices have won the Rookie Tournament).
Kokurenkai Belt - Complete all of Akiyama's side missions.
Kokurenkai Headband - Complete all of Tanimura's side missions.
Kokurenkai Undergarment - Complete all of Saekima's side missions.
Limbo 2 - Night of the Limbo - Complete all of Kiryu's side missions.
Luck Mallet - Complete Challenge Hostesses (complete all hostess side missions).
Lucky Binding - Complete Challenge Dining (order everything on the menu at every restaurant).
Muramasa Blade - Complete Challenge Coliseum (win all tournaments).
Rage Armor - Complete Challenge Police Scanner (solve cases received on the scanner).
Rage Bracelet - Complete Challenge Gang Encounters (defeat all gangs).
Rage Talisman - Complete Challenge Friends (become friends with specific people around the city).
Sacred Tree Arm Guards - Complete Challenge Master's Helper (complete all of Master's tasks).
Sacred Tree Armor - Complete Challenge Saigo's Training (complete all of Saigo's training courses).
Sacred Tree Shin Guards - Complete Challenge Nair's Kumite (help Nair reach her objective).
Substitude Stone - Complete Challenge Revelations (see all revelations).
War God Amulet - Complete Challenge HEAT Action (use all HEAT Actions).
War God Talisman - Complete Ultimate Skills at the main menu.