I don't know if it's been posted further or not but I did find on the internet more specifically on how to collect the 7 happy items and what happens after.
https://tamagotchi.wikia.com/wiki/Tamagotchi_Plus_Color
* Rainbow - Use the Rainbow Watering Can on a partially cloudy day.
* Shooting Star - Use the Telescope on a clear night.
* Four-Leaf Clover - Use the Magnifying Glass, just after planting a seed on a partially cloudy day.
* "Winner" Popsicle Stick - Eat Ice-Candy On-a-Stick. Occurs by chance.
* Stem Floating Upright in Tea - Drink Japanese tea. Occurs by chance.
* Heart-Shaped Cloud - Appears in the sky on a partially cloudy day.
* Hapihapitchi - Use Hapihapi Seeds to grow a tree, and eat a resulting Candy Heart.
I got the tea thing by accident this morning but just got the Popsicle and Cloud after reading this.
There's a video on Youtube showing someone reaching all 7 items and unlocking the ????? in the Door section. In the video, they visit the king, there's a coin and heart drop similar to the apple drop and the result was winning 500 in money.
Also I found instead of waiting for stuff to load in the Door and Food sections, I can hurry it along and keep hitting the B/Middle button. (I'm an impatient person)