It is a popular LCC that operates a limited number of routes in Japan. HND-FUK is one of their biggest ones.

Many of my friends use SkyMark and say it is okay. They fly 737s. Personally, I always take ANA or JAL because their seats are more spacious as they usually fly 777s on that route.

You will be fine on SkyMark, but for just ¥2,000 more I think ANA or JAL would be nicer.