Spinning noise gradually increasing as RPM goes up

[joonoo]

I have an R18 MT and noticed spinning noise as RPM climbs. It's not too loud before 1500 RPM or so but from 2k until I shift usually around at 3k. it was pretty loud. I can barely hear this noise after 5 minutes or so. So I think the noise comes when the car is cold I think. In the morning, the noise was there until I ran for about 5 minutes or so until the engine/transmission got warm I guess. After parking 10 hours during work, at 8:30 PM I start the car and it did have the noise.

I didn't really pay attention before, but same type of noise is always on the car, but much smaller. The noise is like when your car is in reverse gear. It's like... motor sound from those remote control toy vehicles. I'm just worried about it as the noise wasn't as loud as this during when cold. I did get a oil change about 2 weeks ago as well as power steering leak fixed. Other than that, I didn't touch the engine bay except oil level checking which is 3/4 up from Min to the Max level. Power steering fluid is like 1" below Min level (Leak again?) if that matters. I didn't have time to check transmission oil level since I never really done it before and manual talks about actually filling the oil with your finger. I'll try next morning for that.

Since this happens with RPM climb, I'm suspecting it's coming from either engine or transmission and is almost gone with they get warm. This can't be normal right? Tomorrow is sunday and next day is Labor day so... I just wanted some suggestion before I take the car in on Thuesday. Any help will be appreciated!