"Penpa 20xx" series are the renewal versions of our best sellers "Penpa Mix" series. The book contains about 300 number puzzles, includes English explanation. The names and numbers of puzzles included are below. Shikaku 19 Masyu 19 Ripple Effect 19 Numberlink 25 Nurimeizu 25 Heyawake 25 Nurikabe 25 Pencils 20 Sto-stone 20 Nurimisaki 20 Yajilin 29 Slitherlink 29 Kakuro 20