Remember, the only real rule behind Friday 4Komas is that they have four panels. Besides that all bets are off. This is the first time I’ve created a parody of a notable character in a Friday 4Koma. Story and event translations for the mobile app game, Ensemble Stars. Special thanks to everyone that helps me collect screencaps of stories and dialogue for translating! This page was last edited on 7 November 2010, at 05:58. Content is available under Creative Commons Attribution-ShareAlike 4.0 International License. Unless otherwise noted. 3) auto training to unlock 4komas, hence more gems. 4) Uncap materials This is gonna get fairly long, but please bear with me.-1) To be sold for sugar: basic The item shop restocks those exp gems every month, which can be purchased with sugar of the corresponding colour!

So you've gacha'd a lot, got a bunch of R cards and don't really know what to do with them. That's ok! Mahoyaku has a complex game mechanism, which keeps it fun and exciting! As far as my experience goes, there are 3 utility values to the R cards, which are written below:
1) to be sold for sugar: basic
2) to be sold for sugar: advanced
3) auto training to unlock 4komas, hence more gems.
4) Uncap materials
This is gonna get fairly long, but please bear with me.
---
1) To be sold for sugar: basic
The item shop restocks those exp gems every month, which can be purchased with sugar of the corresponding colour! To ensure that you can finish out the stocks every month, normal R cards can be sold for the sugar. A copy of R card will yield 3 sugars of the character's country. For example, selling a R Bradley will yield 3 northern (purple) sugar, R Mitile will yield 3 southern (green) sugar, so on so forth.
2) To be sold for sugar: advanced
The item shop sells a SSR ticket for 720 sugar. SSR! Ticket!!! For freeeeee!!!! So it is a good idea to save up your central sugar for this reason.
Now, it gets a bit trickier at this point because what you'd want to do is maximize and get as many sugar as you can get! And the way to get sugar is by selling the cards. At lv 1 (1 copy), the cards will give the following number of sugar:
N: 1 sugar
R: 3 sugar
SR: 30 sugar
SSR: 90 (but why would you want to sell this, right)
Sounds little? Well, we can get more! By using the bronze petals -- which we don't use anyways -- we can max uncap (+5) and max-lv the R cards and get up to 7 sugar for every R card. Here's a breakdown:
N (+5) at lv 1: 2 sugar
R (+5) at lv 1: 6 sugar << highly recommended!
R (+5) at lv 67: 7 sugar
SR (0) at lv 65: 36 sugar << highly recommended!

4koma Template

SR (+5) at lv 90: 72 sugar
SSR (0) lv 75: 108 sugar
tldr: I highly recommend (+5)-ing R cards before selling them. Accumulate 720 sugar and buy the monthly SSR Ticket!
3) auto training to unlock 4komas, hence more gems.
4 komas are cute. Cute is good. You want to get those sweet gems as well, right? Me too.
That's when those event-related chibis have more added value! By stashing in a party with cards from the same event, you will have a very high chance of nailing the event chibi. Lemme pull an example...
There is a high chance (70%?) of getting a Tea Party Mitile with this setup on auto.
On auto!!!! Sweet : )

4koma Romcom

It is for this reason that I recommend keeping 1 copy of every event R cards. After you've acquired your desired 4komas, the cards aren't quite useful anymore. You can sell them for sugar, or keep them so they can hold nice fashion shows in the room. (I do the latter)
4) Uncap Materials
R cards can be used to uncap SR cards! One R card gives 5% chance of uncapping an SR card, provided that the character is the same. The effect is cumulative too, so you can hoard 20 R cards to uncap an SR card. For example, you've got SR [Splash of Relief] Lennox card that you want to uncap. Any R Lennox card will give 5% uncap chance when you use those as lv up materials. Fuse 20 R Lennox cards and you'll have a 100% chance of uncapping it! Again, this only applies when the character is the same, so fusing Bradley to Lennox won't give any uncap chance.
Personally, this clutters up my inventory and I hate it (lol). Silver petals are fairly easy to get as well, so TBH we can play comfortably without hoarding. But if you're desperate to uncap SRs/SSRs, then this is something that you can keep in mind.
FYI, there're a few things about uncapping in mhyk:
1) Fusing the same card will give 100% uncap chance
2) Fusing cards of the same character + rarity will give 20% uncap chance.

Good 4koma

3) Fusing cards of the same character + 1-rarity-below-the-said-card will give 5% uncap chance.
The above explanation that I gave had elaborated on point (3). It explains how R cards can be used as uncap materials for SR cards.
So anyway, because I haaaate clutter so much, I'm gonna tell you one final tip: hoard smartly if you must! Late on in the game, you'd want to achieve 30,000 score and get those sweet 40 gems rewards. This can be achieved with a party of three lv 75 (initial) daiseikou SRs and a stamina recovery SR. This is the setup that I use, and it works really well. The higher their levels, the better! So you can hoard R Snow, Heathcliff, Chloe, Lennox, Bradley and Murr to fuse for their SRs.
We can still play comfortably without hoarding, tho.
---
That's all that I can think of regarding the utilities of R cards! Tldr:
1) sell for sugar,
2) sell for SSR ticket,
3) keep to unlock 4 komas.
4) hoard for SR uncap material
Hope that helps!
Reference: this awesome Twitter thread complete with pictures and detailed tips and tricks. Bless them

4koma Manga

Supplement: Sugar shop guide