"Neneriko" seems to be a Japanese term, which might be an attempt to represent the word "ねねり子". In Japanese porn videos, this tag refers to content involving young or teenage girls. The term "ねねり子" is often used in adult discussions on the internet and can also mean 'cutie' or 'young girl'. It represents a specific age group (typically considered as under 18) that attracts viewers due to their perceived innocence, youthfulness, and vulnerability.
Note: Age of the performer is important to know because it is against the law to possess pornographic material involving those under 18 years of age in many jurisdictions.