With that being said, if you're pulling your hair out - here's the guide. Obviously, it contains SPOILERS.
(Click on the screenshots to enlarge them!)
Before school starts:
- Withdraw at least $1.00 from your piggy bank. You will need to buy an item from Monty in the playground or buy an item from Nugget.
- Take Cindy's flower from your shelf. (You must've first completed Cindy's storyline for this to become available.)
- Talk to Monty and buy the yo-yo from him. (Optional; there is an alternate method later...)
- Talk to Cindy and agree to be her boyfriend; take the gum from her and show it to Lily. Tell her you think she is pretty. (This the ideal dialogue choice, you will receive your reward later...)
- Talk to Nugget, say you will be his friend and offer him Cindy's flower. He will reward you with the 1st Nugget of Friendship and a strange device.
- First, talk to Nugget. He asks you to bring him the 2nd Nugget of Friendship - which is in plain sight in his cubby. But, Ms. Applegate prohibits you from searching other people's cubbies...
- For this next step, we can either use the yo-yo you bought from Monty in the playground, or talk to Nugget, who will offer to sell you one of his pills for $1.00. Either give Jerome the yo-yo and let him distract the teacher, or offer the teacher one of Nugget's pills.
- Whichever method you use to distract her, go to Nugget's cubby and take the 2nd Nugget of Friendship.
- Deliver it to Nugget, who will then ask you to give Lily a love poem he wrote for her. Lily will only take it if you trust her - which is why it was essential to gain her trust in the playground earlier.
- After Ms. Applegate (high or not) reads out the frankly hilarious poem, return to Nugget for the 3rd Nugget of Friendship.
- Talk to Nugget and Buggs will throw a handful of nasty slop at his head. (Keep your eyes peeled, his sprite keeps the slop in his hair for the rest of the day!) Nugget vows revenge and gives you a poisoned chicken nugget to feed to Buggs.
- Go and speak to Lily, who will give you a doughnut as thanks for what you said earlier and as an apology for reacting the way she did to Nugget's bizarre love note.
- Now go and speak to Buggs. There are several ways in order to convince Buggs to eat the poisoned nugget - you can bribe him with cash (after insulting him by saying he's poor and needs the food) or tell him that either Cindy or Jerome would think he was a sissy if he didn't. Saying Monty, Nugget or Lily won't convince him. (You can also give him the doughnut, but I advise against it, as we need it later!)
- After Buggs has ingested the poisonous chickeny delight, return to Nugget. Buggs will die spectacularly right on cue and Nugget rewards you with the 4th Nugget of Friendship.
- Go over to the sandbox and talk to Nugget. He will reveal his plan to destroy the Principal's statue. Take the device and place it behind the statue when the exclamation mark prompt appears.
- Talk to Lily, be sure to mention Billy's name, which will cause the statue to explode.
- Ms. Applegate will then appear and threaten to send you to the Principal's office. You can either pay her off ($5.00) or offer her the doughnut you got from Lily earlier.
- Return to Nugget, who allows you passage into his Nugget Cave. There is a Monstermon card here, if you have enough spare apples to take it. (You don't often get access to the Nugget Cave, so this is a good opportunity to grab this one.)
- Interact with the memorial shrine Nugget build to honour his missing best friend Billy and place Cindy's flower upon it as a sign of respect.Nugget is moved and will cry, expressing his desire that ne no longer wants to forget Billy and quit taking the Principal's pills.
Show & Tell:
- Show one of your 5-pack of nuggets as your show & tell item. After school ends, Nugget will reward you with his special item - a note from the missing student, Billy.
Nugget's storyline complete!