Its rather a given that Pastel and Parallel are similar because almost everything is the same. I mean, Pastel parallels Parallel. Parallel has the same story and the same characters (who are afraid to admit there love) but it was written earlier. Pastel is the newer story and continues on with many more scenarios but instead to jumping right to being intimate like parallel did, Pastel drags it out quite a bit. There both sister stories with the same mood and slice of life setting. Both are incredible series and before you know it, you'll be cheering the couples on and waiting on edge for them to become more intimate.