What actors and actresses appeared in Oo na... Mahal na kung mahal - 1999?

You are likely referring to the Filipino film "O...M.G.! (Oh My God!)" (1999). There is no record of a film called "Oo na... Mahal na kung mahal" in 1999.

Here are the actors and actresses who appeared in "O...M.G.! (Oh My God!)":

* Aga Muhlach as Michael "Mike"

* Claudine Barretto as Maria "Maya"

* Ariel Rivera as Benjie

* Edu Manzano as Michael's father

* Gloria Romero as Michael's mother

* Jolina Magdangal as Mike's sister

* Bayani Agbayani

* Paolo Contis

* Ai Ai delas Alas

* Maricel Soriano

* Gretchen Barretto

* Rufa Mae Quinto

Please note: This list may not be exhaustive. Some supporting roles may not be listed.