From StrategyWiki, the free strategy guide and walkthrough wiki

Necessary locations

• Home: Mailbox
• Domina: Colorblocks

Enter your house some time after your first quest/event and leave. Pelican will be outside and will tell you pumpkins have taken over Domina. At this point the event begins.

Enter Domina, head to Western Domina and follow these directions.

• Up (starting on map)
• Left-lower left
• Left
• Left
• Left
• Upper left

You will walk in on Bud and Lisa's conversation. Afterwards, walk towards them and this will begin the Bud and Lisa boss fight. You will gain no experience for beating them, however, they will ask to be your apprentices. If you choose to take them under your wing, a later event will be accessible.