A Renzoku puzzle is very much like Consecutive Sudoku. A renzoku puzzle uses a square grid, and each row and column must contain the numbers from 1 to the highest number once and only once. Black dots appear in between some squares. A black dot means those 2 numbers must be consecutive, When there is NO black dot between 2 squares then these squares CANNOT contain consecutive numbers. Here is the link to renzoku puzzles:
You are right. These are very similar to Kropki, the only difference being that dots that represent multiplication by 2 aren't used here. The size 7, 8, and 9 puzzles can be challenging and require a lot of patience.