みなさん、こんにちは!

Just would like to ask if you *need* a visa to enter Japan, if it is only for 2-3 days? I will be going to Korea soon, and would like to visit my friend in Japan and would also like to skip the hassle of applying for visa. As I do not have a flight ticket, itinerary etc yet, will I be rejected if I just apply for a visa?

Anyone who managed to go through without a visa? Or anyone who applied for visa from Korea? Please share your experience.

Technically that is not correct as there are actually a visa-exemption arrangements between the Malaysia and Japan.
Nevertheless,  the word I would use here is that it is strongly recommended to apply for visa before arrival.
http://www.my.emb-japan.go.jp/English/visit.html

Thanks for the reply guys . Most probably gonna book em already.

Also, anyone here has any experience of bringing in more guest than actually allowed in a hotel room? Meaning 1 room but 2 or 3people staying inside. Do they check regularly for these kind of stuff?

Shazzac, it's common courtesy to declare the number of guests in Japan. Of course, you can choose not to heed them, but i believe one should respect their culture in their homeland.

Even at some eateries, you (couples) aren't supposed to share a set meal ! One person one set !