When Rentarou was born, the Love God got distracted while entering Rentarou's soulmate count and mistakenly gave him 100 soulmates instead of one, he says he got distracted because Castle In The Sky was on TV at the time, he doesn't seem to take his job very seriously, getting distracted by simple things and admitting mistakes casually.

The Love God presumably has all the powers a god would have. He is in charge of assigning the number of soulmates to people when they're born. He is also able to move through solid objects like shrine altars.

(Source: 100kanojo Wiki, edited)