[1] Born and raised in the southern New Zealand town of Dunedin, Renton attended the prestigious Otago Boys' High School in his hometown where he played first XV rugby, captaining the side in his senior year.

Tanaka's return to Japan to play Top League rugby with the Panasonic Wild Knights in 2014 saw Renton become first choice number 9 for the Razorbacks.

2015 was a much better year for Otago who finished up in 3rd place in the championship before going down comprehensively to Wellington in the semi-finals with Renton once more being the province's first choice halfback, playing 9 out of 11 matches.

Renton missed the entire campaign as a result of a knee injury picked up playing club rugby earlier in the year.

[12] Serving as back up to All Black Aaron Smith and Japanese international Fumiaki Tanaka, Renton was limited to just a solitary substitute appearance in his first season with the Highlanders.