As an addendum to the stuff I’ve been doing on anime timeslots in the mid-to-late 90s, it’s interesting to note that Kansai-based broadcaster Sun Television Co. actually had a little anime slot of its own, set at Thursday 24:35, which aired a few new shows. Sun TV was not the only current broadcaster of what were presumably UHF anime, and it shared part of its broadcast order with KBS Kyoto as well as Television Saitama, but their slot was listed as the primary one for To Heart by the tv-drama db, a generally reliable source.
Let me be the first to say which station broadcast what first and in what relation to the others is a question that is almost certainly more complex than I treat it as here. I know these shows were aired together on one channel, and not all shared Legend of Basara, so I’m going to define SUN TV as the primary broadcaster for the purpose of outlining the slot.
Since it was broadcasting to a much smaller region of the country (as part of a larger group of stations targeting several regions with the same block), information on it is more fragmentary, but we know it aired the following series during the 90s:
Legend of Basara [04-1998]
Dokyuusei 2 (OVA rebroadcast) [07-1998]
Kakyuusei (OVA rebroadcast) [09-1998]
To Heart [04-1999]
Kakyuusei (1999 TV Series) [07-1999]
As a 10k+ hit and something of a spiritual successor to many early-2000s Kyoto Animation works*, To Heart stands out a bit from the rest of the list. I find it interesting, though, that they first aired a pair of TV-edited Elf-franchise adaptation OVAs in the slot, perhaps partially to test the waters for the upcoming one-two punch of To Heart and Kakyuusei in consecutive seasons.
*In an admittedly primitive sense – much of the in-betweening and motion work for the final 3/4 episodes was outsourced to their studio.