You can watch the first episode of Horimiya legally and safely on these platforms: : Offers Episode 1 for free with English subtitles.
: Often hosts legal streams of the series depending on your region. Watch Horimiya Episode 1 for free on gogoanime
If you choose to use Gogoanime, it is highly recommended to use a robust (like uBlock Origin) and a VPN to protect your device. Safer & Official Free Alternatives You can watch the first episode of Horimiya
: Provides a 7-day free trial of their Premium service, which includes ad-free viewing for the entire series. Watch Horimiya Episode 1 for free on gogoanime