The achievement isn't clear when saying just "Deepen bonds with heroes", the achievement actually requires you to fill the "Bond Meter" which is the meter with the heart inside it when completing a quest or sub-quest with a hero. Once that meter has been filled to the top it should blink yellow, meaning it has been filled. Do this 10 times and congratulations, you have unlocked "But I'm Right Here" for 35G
Happy Achievement Hunting!
GT: Awill