Can I sponsor 3 friends in Group visa?

Hello,

I know this is not a Visa queries related form but if anyone has dealt with same situation ever while applying for Visa (Tourist 7-Days), please share your feedback.

I travelled to Japan last year in June and wanted to do so again next month (April/May) but this time I wanted to take my little brother and 2 friends with me.
So basically we are a group of 4 friends, I am a Freelancer (have been to Japan last year), my brother is student, one of my friend is college student in final year and other one also in final year but doing internship with a IT company.

I tried to search around but couldn't find any info regarding group applications. Basically, I wanted to sponsor/fund the whole trip for the group (though two of my friends will be paying me back later).
I have around $4000USD in my bank account and we have all other require documents, we will be travelling for 5~ days.

Do we just submit the application as normal and I mention in all of our covering letters that I am sponsoring/funding the trip ?
Or do I just have them show their parent/sister account/statement or so ?

Any info will be helpful.

Regards and happy blossoming

What country are your friends coming from?

Same as me, India.
We are all IRL friends.