With the success of the song “Mundong ‘Di Magkatagpo,” Tenten and Angel make their mark in the music industry. Unable to find inspiration in writing new songs, Tenten flies to Paris for a music summit but finds himself in Italy when his flight made an emergency landing in Venice. Meanwhile, Serena starts anew with Gian Carlo and soon becomes comfortable around him again.

While exploring Italy, Tenten unexpectedly runs into Serena. However, nothing comes out of their meeting as Gian Carlo finally proposes to Serena.

Tenten opens his heart for Angel, but what if Serena returns to the Philippines?

In Manila, Serena searches for people and places that can help her regain her memories.

Eager to search for her forgotten identity, Serena goes to the Philippines in secret. Meanwhile, Tenten reconnects to his family and friends, and finally decides to open his heart to Angel.

After browsing Serena's Instagram account, Angel secretly sends her long-lost sister a message and unexpectedly receives a reply. Serena agrees to meet up with Angel after wandering aimlessly around the streets of Manila and almost crossing paths with Tenten.

Angel finally meets Serena and brings her to a bar where she performs her hit song "Magkabilang Mundo." Serena unwittingly sings along and later remembers meeting the song's composer upon hearing Tenten's name from Angel.

Serena's indifference toward Tenten bothers him greatly, until he finds out that she has lost her memories.

Serena is rushed to the hospital because of an upset stomach, and she ends up staying at the Urtolas for the night. Serena gets to know her biological family better, and unknowingly reconnects with Tenten through a phone call.

As Angel convinces Serena to meet their relatives, she gets Tenten to attend the family reunion as well. In a turn of fate, Serena and Tenten go to the same store to prepare for the gathering. Tenten sees Serena, chases after her, and finally learns of Serena's relation to the Urtolas.

Tenten comes to a decision of telling Angel the truth about who he is in Serena's forgotten past.

Upon coming home from the Urtolas' party, Tenten reveals to Dodoy and Taps that Serena is Angel’s long-lost sister. Learning that Serena has amnesia, Dodoy and Taps try to encourage Tenten to help Serena remember her past. Tenten, however, refuses to do so, leaving his parents puzzled.

Hearing Tenten's newest composition drives Serena into a severe emotional turmoil that worries everyone around her. This incident pushes Tenten to decide on confessing the truth behind Serena's condition, but Binggoy goes home just to stop Tenten from doing so.

Dodoy punishes his sons by sending them to jail. As he and Binggoy exert effort to regain their father’s trust, Tenten comes to a decision of telling Angel the truth about who he is in Serena's forgotten past.

After learning of Serena’s forgotten past, Angel plans to reveal the truth to her sister. However, Alice urges Angel to keep mum in order to protect their family.

A new opportunity comes along Angel and Tenten’s way when they receive an offer to do an album as a duo. Upon learning about her sister’s upcoming provincial tours with Tenten, Serena decides to join them and even urges the entire Urtola clan to tag along—a move that alarms Alice.

Serena retrieves indistinct memories upon hearing “Ang Suso” and after seeing a local drum and lyre corps in Angel’s provincial tour. Tenten, on the other hand, strives to avoid Serena as Alice wishes.

Jei Jei creates a plan to trigger Serena's memories by bringing everyone to a resort where fireflies abound. The plan fails, but Serena recounts firefly stories from Luciana and Gian Carlo, surprising Tenten because he was edited out of the retelling. That night, however, Serena spots a firefly that leads her to Tenten.

Jei Jei successfully scares Serena out of her room, leading her to seek Tenten’s help in the middle of the night. After recalling a similar situation in the past, Tenten calms Serena with the same words she told him before. The next day, Serena surprises everyone with her sudden desire to go to Bohol.

Serena learns about Tenten's nickname, and becomes curious about it after being mentioned by Gian Carlo before. Soon, Serena becomes alarmed when she starts imagining herself in Angel's place around Tenten. Seeing Serena struggle, in turn, makes Alice feel guilty for keeping the truth from her daughter.

Despite their intentions to keep away from each other, Tenten and Serena find themselves composing a love song together in the middle of the night. Meanwhile, Uge calls for an emergency family meeting regarding Serena's situation.

Tenten summons all his courage to break up with Angel and to admit that he still loves Serena. Serena, on the other hand, begins suspecting that her family is hiding something from her.

Angel's breakdown compels Uge to ask Tenten to keep his distance from his daughters and from matters concerning only the Urtolas. On the other hand, Serena decides to talk to Tenten without her family's knowledge, after learning from her psychiatrist that he may have something to do with her forgotten past.

The Ibarras take Serena to their farm, where she gets to learn more about Tenten from his family. Upon learning about the situation, Tenten sets aside his meeting with Angel and hastily follows his family in fear of the truth being known by Serena already. Angel, in turn, struggles to heal her broken heart.

Just as when Serena finally gets the opportunity to ask Tenten about the indescribable attachment she feels towards him, Angel discovers that Serena is with the Ibarras and immediately informs their parents about it. Soon, Uge’s phone calls not only interrupt Serena and Tenten’s conversation but also remind Tenten to leave the task of revealing the truth to the Urtolas.