This information is NOT the official height of Haru Kose. This is an estimate height based on her physical appearance and background information on the game.
Haru Kose is portrayed as an adult Japanese girl who serves as a “High Priestess” to a certain shrine. Assuming that she is an adult, we will correlate her visual scale along with the average Japanese female height in Japan to figure out her most probable height range.
In one article from WannaBeTaller, it was mentioned that an adult Japanese female (age range: 20-24) have an average height of around 5 feet and 2 inches. If such is the case, then Haru Kose may fall into that same height range considering that she is indeed heavily portrayed as a Japanese female in the game, however, our visual observations of her character model in the game contradicts that this might not be true.
Haru actually seems to be a lot taller than the average Japanese girl, as can be seen in this Youtube The Tale of Onogoro | Full Playthrough | 60FPS – No Commentary Video by 99TH VR and on several Google Search Images. Haru Kose might actually be somewhere around 5’5 or 5’6. This is especially proven when she is scaled alongside a male character named Masatake Arakida.
When both Masatake and Haru are placed beside each other, there is only around 2 to 3 inch height difference between the two. So as mentioned on the same WannaBeTaller article, if the male Japanese average height is around 5 feet and 7.8 inches, then it would be not so factual to conclude that Haru Kose is around 5’2. (Hikaku Sitatter Height Comparison Tool helped us visualize this height difference)
In the end, we give a conclusion that Haru Kose is actually a fairly tall girl for a Japanese. She is probably somewhere around the height of 5 feet and 5.5 inches tall.