I've come across a few people that have been a little perplexed by the characters in Wandering Son (Hôrô Musuko), and I don't blame them. The series is perhaps a little harder to follow in manga form, but the lack of distinguishing characteristics may make the characters unidentifiable. While the actual review will cover the differences between the players in the show, here is a translation of the relationship chart obtained from theHôrô Musuko website. Click on the image to get a larger view of the chart.
(The heart marks between images should mean there is a mutual relationship. I left out the obvious relationship between the siblings Shuichi and Maho; it should be obvious who the two are.)