@moichispa Mirin is usually listed specifically when cooking, differentiated from sake, as most commercially available mirin even within Japan contains added sugar and preservatives. Real mirin/hon mirin is fairly hard to find. If the recipe specifies sake, it usually means actual sake, tho it doesn't need to be high quality- use the cheapest brand you can find. Chinese rice wine/cooking wines can be used in some instances like this dish- the dish listed in the chapter is basically a "chashu", which is a Japanese adaptation of a Chinese braised pork, so the flavor profiles will be similar (both chinese rice wines and japanese sake use the same base fermenting mold that creates similar umami flavors, tho the processes and results differ greatly). If making the swap to something like Chinese cooking wine, be aware that many Chinese cooking wines have added salt.
ah, edit- what freak of nature said too- japanese cooking sake is akin to chinese cooking wine as well- added salt. and if u only have mirin, that's fine too- but use less sugar.