From Halopedia, the Halo wiki
In 2552, he was a civilian student of a medical school, sharing an apartment room with his friend and fellow student Kamal Zaman. He was a nerdy young man with a basic understanding of cooking, a good sense of humor, and a healthy sex drive. He desired to have a girlfriend, but was clueless when it came to dating.
He purchased a book intended to teach him how to date. Making himself out to be more knowledgeable in that arena than he was, he offered to coach Kamal in dating. Kamal arranged for Hiro to feed him live dating advice through an earpiece, while Hiro listened in on the date through Kamal's chatter. Unfortunately, Hiro's utter ignorance of how to make Kamal appealing to a person not interested in technical details of medicine led to the date walking out on him.
When Kamal attracted the ire of gangster Aiden Maki, Kamal persuaded Hiro to help him with a similar chatter/earpiece scheme to listen in on Kamal's business dinner with Aiden. If Aiden were to become violent, Hiro would enter a button sequence on his chatter that would send a "Police officer under fire" message to the local police force with Kamal's chatter as the location to ensure his swift rescue. However, Aiden instead tested Kamal with a dirty cop hassling him to see how he would respond under pressure, and Kamal told Hiro to enter the sequence backward, which sent the message with Hiro's chatter as the location to make the cop leave Kamal and Aiden. Hiro entered the sequence and, on Kamal's instruction, smashed his chatter and threw it down the sewer before barely getting away as cops flooded the area. He waited for Kamal to get home and angrily confronted him, but was able to forgive him when Kamal shared his expensive and delicious Coral cuisine leftovers.
Kamal worked a job for Forihoff through Aiden, and Forihoff paid Kamal handsomely in poker chips. Hiro helped Kamal examine them and jokingly applied sexual references to them, calling a toffee-colored chip "pantyhose-colored".
As Kamal cozied up with Aiden's girlfriend Sophia Bossedon, who Aiden encouraged to spend time with Kamal as a means of keeping him happy, Hiro made friends with her as well. They teased Kamal together and joked that they were having an affair.
After news broke that the planet Coral was glassed by the Covenant, Hiro was the one to break the news to Kamal that his home planet was destroyed. Hiro presumably comforted Kamal about the death of his family, which he thought was on Coral when the Covenant hit. Actually, Aiden had them sent to Earth as payment for Kamal's service, and Hiro helped them get settled in the apartment while waiting for Kamal to return. He went shopping for cooking ingredients.
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