In the '90s, they starred in two movies: Bakit Labis Kitang Mahal and Sana Maulit Muli.
But up to now, even if both have their respective families, Lea and Aga would manage to catch up with each other.
On Twitter, the world-class performer wrote, "Aga is probably the closest artista to me."
Anne Curtis and Luis Manzano
These BFFs actually used to date each other.
Anne even admitted in one of her interviews with PEP.ph that he's the guy she'd "like to marry."
But the two have long decided to be just the best of friends.
Angelica Panganiban and John Prats
Angelica was the "best man" of John when he tied the knot with Isabel Oli on May 16, 2015.
The actress didn't make it to his stag party, but she left this touching message on Instagram.
"Petty bes!! Ikakasal ka na!! Sorry na miss ko ang party niyo tonight. Babawi ako sa wedding day!
"Nanonood ako ng Gmik kanina sa Jeepney TV. Sobra 'kong tinamaan sa pinagsamahan natin.
"Mga bata pa lang tayo, palagi na tayong magkasama.
"Ngayon, ikakasal ka na. Sa susunod, binyag na pupuntahan ko. I'm very happy for the both of you, pets."
Bea Alonzo and Enchong Dee
Enchong has been Bea's travel buddy and "true friend" since 2009.
In one of her interviews, she said, "Para ko na pong kapatid si Enchong. Mabait siya, masarap kasama at saka matakaw.
"Sobrang naging close po talaga kami ni Enchong.
"Yung tipong pag may mga importateng events sa buhay ko, nandiyan siya.
"At saka ganoon ako ka-komportable sa kanya."
Maja Salvador and Enchong Dee
They had the chance to work with each other in some Kapamilya projects.
But the two have long decided they will never be real-life lovers.
Enchong previously told PEP, "Gusto kong pangalagaan yung pagkakaibigan hanggang sa tumanda kami.
Maja Salvador and Rayver Cruz
They were once linked to each other and used to be screen partners.
But Maja said in one of her interviews six years ago, "Yun nga ang tanong namin sa isa't isa, 'Bakit hindi tayo nagkaka-developan?'
"Click na click naman kami. Kung ano yung mga gusto ko, nasasabayan niya, ganun din ako sa mga gusto niya.
"Siguro enjoy lang kami sa kung anong meron kami ngayon."
To date, they are dance partners and travel buddies.
Lovi Poe and Ben Alves
But their closeness was developed on the set of Beautiful Strangers.
They're simply "kumportable sa isa't isa."
Alex Gonzaga and Robi Domingo
These two hosts are both kwela, wacky, and incredibly good friends.
Robi once said of his friendship with Alex, "Si Alex kasi, she's the sister I never had."
Bea Binene and Kristoffer Martin
He was Bea's last dance at her debut.
Kristoffer explained, "Kami kasi ni Bea, mas alam namin yung kadulu-duluhang sikreto ng isa't isa.
"Hindi naman sa baka isipin ng ibang tao, na akala nila may secret relationship kami.
"Legit best friends kami.
"Sobrang tingin ko sa kanya, baby sister ko, ganun.
"Kumbaga, yung tiwala namin sa isa't isa, 100 percent."