I'm not sure what you mean by homemade but there's a good Japanese Market on the west side of Houston. I do believe I've seen mochi in the prepared food section of their refrigerator but I couldn't say for sure. It's a small store.
11146 Westheimer Road
Houston, TX 77042
This is very helpful. Thank you. I'm interested in where I can find mochi generally throughout Texas, and I'm also trying to find out if anyone actually makes it in Texas, as in do they take the rice and process it themselves. Even just the name of a shop that sells mochi is helpful. I appreciate it.
99 Ranch Market and Hong Kong Market on Bellaire may also. Haven't heard of anyone making it here in Houston. It's a long process. I've only seen it made once and that was for a Japanese Festval in Los Angeles. I have gotten mochi ice cream at Hong Kong Market and I've seen it at 99 Ranch Market. Not exactly what your looking for though.