The following contains spoilers for Episode 14 of Komi Can't Communicate, "It's Just a Typhoon," now streaming on Netflix.
At its core, Komi Can't Communicate is a series that spotlights various forms of social anxiety. Even the titular heroine's name, Komi Shoko, is a pun on the Japanese phrase "komyushou," meaning "communication disorder." True to her name, much of Komi's storyline is centered on her desire to be more social yet struggling to overcome her extreme social anxiety. As a result, she has trouble verbalizing her thoughts and resorts to communicating with her friends and classmates by writing in a notebook.
As Komi started becoming more comfortable around her friends, she also started becoming more confident in using her voice in social situations and has done so occasionally. The first instance in which she managed to briefly use her voice to communicate was during her first phone call to Tadano Hitohito in Season 1. Since then, she's been able to briefly talk on the phone, but not often enough to break out of her comfort zone. The few times she managed to use her voice during a social gathering was at a summer festival with Tadano and then at her school's festival. Komi Can't Communicate Season 2 is continuing to further flesh out this development.
In the story "It's Just a Typhoon" featured in Episode 14 of Komi Can't Communicate, Komi prepares to go to school as she normally does every morning. Unbeknownst to her, a typhoon struck Japan overnight, and she is surprised to see a torrential rainstorm so early in the morning. Her mother Shuko immediately informs her that her school called to let everyone know that classes are canceled for the first part of the day until further notice.
Having seemingly never experienced a typhoon before, Komi sits in front of the large living room window to watch the torrential rain out of curiosity. At one point, she even draws a cat on the fogged window out of boredom. She is immediately caught off guard, however, when a major lightning strike knocks the power out in her area. This makes her quiver with fear, and she is immediately comforted by Shuko like a cat. Unfortunately, her mother then decides to check the house's main breaker box with her brother Shosuke, leaving Komi to deal with her fear of the storm alone.
Luckily for Komi, the moment her mother leaves the living room, Tadano calls to check up on her and make sure she hasn't chosen to walk to school during a major storm. This helps to calm Komi's nerves until Shuko returns. More surprising yet, Komi's fear of the storm makes her forget her social anxiety, and she is able to hold a verbal conversation on the phone. This surprises Shuko, who isn't used to seeing her daughter speak on the phone for so long. She's even less used to hearing her daughter's voice on occasion, much less for a lengthy period of time.
While Shuko isn't fully aware of Komi's close relationship with Tadano, she does take notice of her daughter's progress. Prior to Komi becoming a first-year high school student, she was very much a loner with very little incentive to engage in human interaction. Since befriending Tadano, Komi has made a small group of friends that she brought home once, which -- for Shuko -- was a huge step forward. Now that she has witnessed this profound change in Komi's communication habits, it won't be long before Shuko catches on to Komi's romantic attraction to Tadano, especially if he's the only one who's getting her to talk.