Halfway point

Between Kokomo and Somerville (Ohio), you have a few options depending on the exact route you take. Trippy suggests Springport (Indiana):
https://www.trippy.com/halfway/Kokomo-and-Somerville-OH
But that's taking more local roads, so if you take 31 south to I-70 east, then you could try Greenfield (Indiana) or if you're not too picky about the exact midpoint, then really the best option for tons of restaurants is Indianapolis somewhere close to where you get onto I-70.