there is! if you have a girlfriend character present, pressing buttons on the P2 controls will grant control over the girlfriend character directly. It's very pop-in/pop-out friendly, so P2 tag in and out fairly freely.
There are potentially some weird interactions with the second character, it's hard to test everything. P2 shares meter with P1, gets back up automatically when getting knocked out for free (but does cause P1 to crumple when P2 gets KO'd), can use the GF button to return to P1, and has their own health bar but reduced defense. In the most recent update i was able to get targeting to work separately for the 2 characters, so they can face enemies and be targeted by enemies independently of each other.
One trouble with the system is not all characters have very complete movesets, and some characters haven't had attacks assigned inputs, but most of the available GFs through non-debug means are fairly functional