Tokyo to Sapporo, airlines

Hi i'm planning to go to Sapporo this December during our japan trip.
Because i've read a lot of complaints about Vanilla Air. I'm not so sure with the others. Given that i dont speak/understand japanese and therefore would find it difficult to communicate with the staff in case of complaints or inquiries, which cheap airlines would be good? :)
This is also the first time i'll be flying domestically in japan

If you want best service, just go with ANA or JAL. Tokyo-Sapporo is a very competitive route, so they are not much more expensive than the budget ones.

Peach Airlines will have a sale starting tomorrow (26 August) which includes your route and time, maybe you should check it as well.

I have used both Japan Jetstar as well as Perch Air. If English is your priority, Jetstar would be a better option. Otherwise, they are both similar.

Thanks for the replies, i think I'll go with jetstar.
Another questiin though, is it common to have flights delayed in december (due to snowstorms or airway traffic, etc.) because im planning to arrive on dec 26 then fly to sapporo in dec 27.
Do you think its okay or i need to extend my time allowance in case of delays?