For using Last name "Hachiro" is not matched exactly. (already mentioned)
"Hachi" means "8/eight" usual but meaing from
- son of 8th
- born in AUG
- Japanese lucky number calling "suehirogari(kanji shape)" mostly.
"-ro(-rou)" is one of boy/male name but now Hachiro is already older as sound.
So picking up from real last names list(lower number of list) may easier.http://www.japan-guide.com/forum/quereadisplay.html?0+154379
If relly like "hachi" as sound you can find "ͺ(hachi/8)"
or other I(bee),«(bowl) using names not so hard.
ͺ¦ "Hachiman" is the most.
(ͺ¦ based from shrine "Hachiman-sama" usual)https://en.wikipedia.org/wiki/Hachiman
If that woman/girl's charactor is heel/bad/ Iξ"Hachiya"
means "bee arrow/as needle" may matched :)
Kiyoko's kiyo(΄/) means "clean" but she is,,,@
Also "-ko(q)" style already overed as naming trend "Kiyomi" is better.
This "-mi" is "ό" a lot means "beauty/sexy" matched more for woman/girl name.
Basically most Japanes name meaning from somthing of Nature.
Recent Governor of Tokyo Yuriko Koike (¬r Sq Koike Yuriko)'s
r(ike) means "pond" and S(yuri) means "lily(flower)".https://en.wikipedia.org/wiki/Yuriko_Koike
BTW,which era's story?
If long long ago... modern style naming may not matched.
If over 100 yrs before only "Kiyo" or "Okiyo(as nick)" best than Kiyoko.
this is most famous how to make main plot.https://en.wikipedia.org/wiki/Hero
(This is not only for adventure story)