The phrase "to become closer" means to develop or strengthen a bond, relationship, connection or friendship between two people or things. Full definition
In regards to your question - I think becoming close friends with investors who are doing the type of investing you want to get into is the best way. (biggerpockets.com)
Can you really become close with characters in a game? (metacritic.com)
I can imagine how lovely it must be to bond in person with people who become our close friends through blogging. (easyanddelish.com)