Play mission 5 as Kintoki. Make sure you have his second or third axe. Try to kill as many Stone Golems as possible at the end of the level. You will be guaranteed at least 2,000 gold pieces each time you finish the level.
Note: You must be up to the stage where you fight both centipedes. Use Tsuna and his second weapon, Thunder, and follow these directions. When you first start the stage, lock on to the red centipede. Try to stay on the center ring through the entire fight. Wait about three to four seconds and he should swoop down towards you from the circular path that he flies in. When he gets about halfway towards you, double jump straight at him and do Tsuna's heavy attack. This should take him down to about half health, and an intermission sequence of the other centipede coming out will begin. You must now worry about both centipedes shooting electric balls at you -- be careful. Also, watch out for the red centipede's electric shower (a little flash of electricity around you). When you see this, jump to your far left or right while dodging the electric balls. Keep doing the same thing to the red centipede (waiting for it to swoop down at you, then doing the power attack).
This should kill him. When he dies, the female centipede will say "My Liege, nooooooo!". When this happens, try to lock onto her. Do not worry about the electric balls and the showers, as they will stop. If she flies around for a little while then disappears from the screen, wait until you see the tip of her feelers come into view from the top of your screen and press Y. If she flies around for a moment before coming down low and snaking across the ground, wait for her to get close and press Y. If she flies around for a while then comes down low and dives under the water, get directly in her line of sight and double jump as she pops back out of the water to leap over you, and press Y. You will hit her as she jumps over you. If you defeat both centipedes in enough time, you should get about 25,000 gold and 60,000 experience points.
Kintoki's second weapon (Blazing Axe)
Complete Stage 8 with Kintoki.
Raikoh's second weapon (Divine Blade)
Complete stage 14 as Raikoh.
Soul Devouring Gourd
Get over 3,000 combos in stage 5.
Spirit Pin
Successfully complete stage 6 in 2 minutes 20 seconds or better.
Start with Moonlight Sword available
Have a completed saved game file on the hard drive from Otogi: Myth of Demons with the Moonlight Sword in your inventory. The Moonlight Sword will be available for purchase at the start of Otogi 2: Immortal Warriors.
Suetake's third costume
Use characters over 200 times.
Unlock Kintoki's second weapon
Complete Stage 8 with Kintoki to unlock the Blazing Axe.
Unlock Kintoki's third weapon
Complete Havoc Mission 12 to unlock the Red Lotus.
Unlock Raikoh's fourth weapon
Buy it from the shop during 2nd Play for 317,000 gold to unlock the Moonlight Sword.
Unlock Raikoh's second weapon
Complete stage 14 with Raikoh to unlock the Divine Blade.
Unlock Raikoh's third weapon
Complete Havoc Mission 17 to unlock the Falling Star.
Unlock Sadamitsu's second weapon
Complete Havoc Mission 4 to unlock the Shrieking Blossom.
Unlock Sadamitsu's third weapon
Complete stage 20 in two and a half minutes to unlock the Black Wings.
Unlock Seimei's second weapon
Complete stage 13 as Seimei to unlock the Twin Dragons.
Unlock Suetake's second weapon
Complete Havoc Mission 7 to unlock the Eight Truths.
Unlock Suetake's third Weapon
Complete Havoc Mission 13 to unlock the Divine Punishment.
Unlock Tsuna's second weapon
Complete stage with Tsuna to unlock the Thunder.
Unlock Tsuna's third weapon
Purify both Centipede Demons in Stage 22 to unlock the Wrath.