Episode Summary
Su Chengcheng's secret is out! Tang Qi reveals he's known all along about her transformations. After a confrontation and a heartfelt demonstration of her abilities, Tang Qi seems to forgive her but is clearly hurt. Their interactions become awkward, marked by a near-confession in an elevator and Tang Qi's jealousy over Su Chengcheng's interaction with another man. The episode ends with them working together, somewhat unintentionally, to promote a new product that evokes memories through scent, with the elderly folks they are marketing to responding positively.

Spoiler Alert
In Episode 23 of "Filter", things get intense. Su Chengcheng, in her disguised form as Su Miao, fights off some guys who were following her. When the police arrive, they take the pursuers away. Tang Qi, who witnessed the whole thing, gets up and stares directly at Su Chengcheng. He takes off his sunglasses, revealing that he can see perfectly. Su Chengcheng is thrilled but also panicked, still trying to keep up the lie. But Tang Qi reveals he's had his sight all along and has seen all of Su Chengcheng's transformations. She's completely flustered, has no idea how to explain herself, and runs away.
Su Chengcheng confides in Lin Yuan, unsure how to explain everything to Tang Qi. Just then, Tang Qi messages her, demanding an explanation. Su Chengcheng knows she has to come clean, even if she's dreading it. She meets Tang Qi and, in front of him, transforms into all the people and things she's previously impersonated. Tang Qi, after learning the truth, doesn't say much. He simply says he'll let bygones be bygones and leaves. Su Chengcheng thinks he's forgiven her and asks if she can still come to work, but she sees the redness in Tang Qi's eyes and realizes he's deeply hurt. She's speechless as he walks away.
That night, Su Chengcheng is a mess. She messages Lin Yuan and her sister in their group chat, telling them everything. The next morning, she runs into Tang Qi in the elevator at work. She's awkward and tries to make an excuse about getting breakfast to get away, but Tang Qi stops her. As the elevator rises, Tang Qi moves closer to Su Chengcheng, backing her into a corner. It turns out he just wanted to tell her a button on the back of her clothes was undone, and he offers her his jacket.
Meanwhile, QianNiao Ji company has developed a new product called "Baiju," and they're brainstorming its meaning. Su Chengcheng thinks of her childhood dream of being a princess. Later, as she's leaving work, Su Chengcheng sees Tang Qi and uses returning his jacket as an excuse to approach him. Tang Qi is cool and distant, simply thanking her. They stand awkwardly waiting for the elevator, and Su Chengcheng makes another excuse to avoid riding down with him.
Su Chengcheng goes to a dessert shop and chats with a male acquaintance about which dessert to choose. Tang Qi happens to see them laughing together and, overcome with jealousy, calls Su Chengcheng to ask what she's doing. She's actually trying to find products for a company marketing campaign and visiting some elderly folks, so she tells Tang Qi she's working. Tang Qi misinterprets this, thinking she's lying.
Su Chengcheng gives the desserts to a group of elderly people, along with samples of the new company product. The seniors are initially skeptical, thinking she's trying to sell them perfume. Tang Qi also visits his teacher, bringing him plants and the new product. His teacher realizes Tang Qi's concept is to use scent to evoke memories but hasn't figured out how to present it. Su Chengcheng uses photos to help the elderly people recall happy memories, and at that moment, a fragrance wafts in – it's Tang Qi. They introduce the new product, and although the seniors were initially resistant to perfume, they change their minds after smelling it and are very satisfied. Tang Qi is touched by Su Chengcheng's efforts to promote his product.