This extra mode is pretty interesting but also hard to describe the gameplay ^^;
The high-level goal is to max everyone’s ‘love love’ level within 50 days so you can see their character-specific conversation at the end and receive items from them.
In the meantime you complete objectives given by Monokuma, assigning each character the task of gathering materials or cleaning.
The love love levels don’t carry over to next playthrough and you can only max maximum 5 characters in one playthrough (limited by the ‘date tickets’ awarded by Monokuma when you complete objectives).
Two trophies, ‘collect all items’ and ‘see all character-specific endings’, require completion of this goal.
Some tips I found:
Focus on raising gathering levels
Each character has 2 stats: gathering and cleaning. Craft the items that level up gathering level and use them to max everyone’s level. Use the items only after the characters reach level 5 though; before that it’s pretty easy to raise the level just by making them do the gathering. But use the items before playthrough is over since they don’t carry over.
You only need 1 or 2 cleaning experts
Unlike gathering, you only need 2, or even just 1, people with max level on cleaning. When they clean, the increase to hygiene gauge is enough to offset its decrease, and even more so with the tools.
Make all the tools first
The ‘tools’, although they don’t carry over to next playthrough, act like forever-on buffs for the duration of the playthrough. The tools increase materials gathered, decrease health consumption, and increase cleaning effect, all of which are desirable effects.
Don’t let materials reach 99 in inventory
Once you have max gathering levels it’s pretty easy to gather large number of materials unknowingly. Use the materials to craft items which might be required for next objectives, or even healing items.
Check wiki on best responses during conversations
You need 10 hearts to max a character’s love love level. The best responses increase level by 1 heart (so minimum 10 dates). Only certain date spots ensure (depending on character) that best choices are always available. There are some ‘difficult’ characters where no spot has guarantee (so reload the game when unlucky).
Complete the last objective
Unlike the second game’s similar mode, you have to complete the last objective of this mode. Otherwise you won’t be able to see character-specific endings even if you maxed their love love levels. I fell for this on my first playthrough, which kinda sucked.
Here’s my progress so far:
The heart sign on the leftmost character means I’ve maxed him on previous playthrough.
Rest assured I’m doing the guys first because I’m saving the best for last ^^;
On fourth playthrough now… I should be able to accomplish it by fifth playthrough.