As you can see below they look very similar and just like TANJIRO, SUMIYOSHI was very nice. TANJIRO after seeing YORIICHI TYPE ZERO said the face looked familiar. And also these "inherited" memories TANJIRO gets of Yoriichi is actually him "recalling" his conversation with Yoriichi as SUMIYOSHI. He even remembers the exact details said.. Demon Slayer season 3 introduced us to Sumiyoshi, who looked exactly like Tanjiro. Here's everything you need to know about him.
The reason he and Tanjiro look so similar simply comes down to genetics. I do believe the creator should've made it easier to differentiate between the 2 somehow, other than the lines on Sumiyoshi's forehead, but I don't think it matters that much. Now, for the fact people are weirded out by his wife looking like Nezuko.. Sumiyoshi is Tanjiro's ancestor. 0 Nezukosomething·4/12/2023 Sumiyoshi is Tanjiro's ancestor so ofc he looks like him :) 0 Depress Giyuu·4/12/2023 He is also the first of the komado family to learn sun breathing