The shift is part of a major overhaul of the organisation, which also includes changing its name to the Otepoti Collective Against Sexual Abuse (OCASA).
The move has been met with cautious optimism by the head of a New Zealand male survivors group, who said the more support organisations could work together, the better.
OCASA development co-ordinator Angelo Libeau said the historically women-only organisation had changed its constitution to work with people of all genders.
"There was a lot of complexity around what it actually means to be a safe space for survivors.
"We said `if we're going to make these changes, can we still maintain our feminist philosophies', and we talked about it for a really long time, and then we went `absolutely you can - it's about how you manage the space to keep everybody safe'."
He described the change as "quite huge".
"There's a lot of different things happening in one go."
As for the name change, Mr Libeau said that was partly because of community feedback.
"It wasn't necessarily representative of what our service can provide, because people have a really set idea of what `crisis' means, or what `rape' means, so we took that on board.
"It's not necessarily a softening of it, but it encapsulates the wider work that we do."
Much of the organisation's work was around supporting people in the longer term, he said.
The organisation had about 100 people on its books, but each person had a complex variety
of needs, he said.
Male Survivors of Sexual Abuse Trust chairman Phillip Chapman said Otago was leading the way in terms of communicating with the organisation.
He and other members of the board had met OCASA members several times to determine how better to work together.
"Otago's at the forefront of doing that - that's the first Rape Crisis group that we've actually sat down with."
He said the move was a positive one.
"We're all working with victims of sexual violence, and the more services that are out
there, the better."
But he acknowledged it would require some changes.
"If you're only working with female victims, you don't get the most pleasant view of men.
"So to start working with them, it's a whole switch in ideology. There's got to be a switch in thinking. There needs to be training in this area because there are big differences between male victims and female - they react quite differently."
A rebranding event for OCASA will take place tomorrow at Petridish, at 7pm.