It is the misspelled form of "I like you" from a bad Thai keyboard setup, which appears in the BL 2gether series. If someone sends you this message, it means he or she likes you.
Those who watch BL series will understand the story of why this mixture of letters and symbols ended up meaning "I like you" or, interpreting the bad spelling, "I loke you".
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!