companion, colleague, utensils
伙 centers on a person you share a close connection with: a companion or colleague. The utensils sense is a separate, less common meaning that does not clearly connect to the main idea.
伙 combines 亻 (person) with 火 (fire), but the historical origin is uncertain. It may have originally referred to a cooking companion or shared fire, but this is speculative.
A person 亻 beside a fire 火 suggests a companion sharing warmth or a colleague working together around a campfire.
For カ, imagine a companion named Carl sitting by the fire: Carl -> カ, and he is your trusted colleague.