I just wanted to UPDATE this thread for possible technical reference in future for my fellow tsikoteers who also own a Toyota Hilux and might experience such problems someday.

I had it checked few weeks ago. As what my mechanic said, there's nothing wrong with other components of my starter except the encircled part of the bendix drive which I will upload below. The encircled part is a trimmed part of the shaft or the metal tube something of the bendix drive assembly. I personally got the chance to hold it and it's let say 1 or 2 millimeters deeper; it's really small but you can definitely feel the difference. It happened probably due to wear and tear since the car almost have 208,000+ kilometers on it. My mechanic told me that as time goes by, grease goes into that tiny trimmed part of the shaft which makes the drive or something (The other hand of the mechanic) to not push completely the pinion gear to the flywheel so it just spins freely on that trimmed part, thus also causes the loud and nasty grinding noise which I uploaded on youtube. The link is available on my recent comments.

Anyway, I met someone in manila who owns an alternator and starter shop and told me he has a surplus starter for my Hilux. It's an OEM Denso, just surplus; Made in thailand, same as mine. They're identical so I was able to get it replaced with my starter.

Fast forward, it starts now with just one click, but it slides a little. Sounds like the pinion gear and the flywheel slips a little bit when engaging, though it does create a noise, it's somehow less noisier and less nastier than my previous starter. The seller told to just observe for a few days because maybe the starter is still on an "Adjustment Period" right now and will just normally fit the flywheel after days of usage; but my mechanic said that if after a week it's still there, he suggested I visit his shop so he'll be able to remove and open the surplus starter, maybe it needs some lubricating or it needs to refitted well again matching the flywheel or last resort, he will try to swap the bendix drive of the surplus starter to the original starter.

I will post tomorrow the link of the sample video of how the surplus one starts and I will update again this thread after a few days to a week after I have got to bring my car to the mechanic and had fixed everything that needs fixing. Thanks!