You are naturally similar in energy and temperament, because your birthdays are very close together, even if you were born in different years. Think of the potential between you as your own natural energy, magnified to double strength. This can work in one of two ways.
Either your connection flows really well -- you understand one another as no one else does, and feel as if you possess twin souls; or all the more trying personality traits that you both share come to the fore, creating problems for both of you. It may be like looking into a mirror -- a very honest one. The truth can hurt sometimes! Especially when it means looking at traits in your own character that are less than stellar. For example, two dreamy and indecisive people might never get anything done! Or two fiery, opinionated types who are quick to debate any issue may find that all they ever do is argue. The good news is, your needs for closeness and independence range on similar scales, which means your rhythms stand a good chance of being in sync. However, again, there lies potential for trouble, and it depends on other factors in your charts, not just your Sun signs. Any tendency toward aloofness and independence could mean that the passion that exists between you may not be enough to keep the connection strong. But if you both possess natures that ordinarily strive for harmony and intimacy, you're likely able to build a strong and devoted connection.