The Pencil Puzzles 20xx series are the renewal versions of our best sellers "Penpa 20xx" series. The book contains about 260 number puzzles, includes English explanation. The names and numbers of puzzles included are below. Akari 27 Suraromu 23 Ripple Effect 24 Shakashaka 27 Double Choco 24 Evolomino(New Puzzle) 21 Yajilin 27 Heyawake 27 Slitherlink 32 Kakuro 20