Higashi Rena was a teenager who competed in KUNOICHI six times. Her first appearance was KUNOICHI 3 when she was only 10. She shocked everyone by making it all the way to the Samenso before slipping and falling into the water. KUNOICHI 4 was the first tournament where she competed with her mother: Higashi Yuko. She aced the Buyoishi but tripped over her foot on the Fuchawatari and dove into the water. She returned for KUNOICHI 5 and made it further but failed the Haso Tobi because the pedestal from KUNOICHI 3 was removed. She then competed in KUNOICHI 6 where she passed the First Stage with 8.04 seconds remaining. She had the sixth best time in Stage 2 and advanced but she failed the Kenzandou in Stage 3 after she lost her balance on the first jump. In KUNOICHI 7, she failed the Haso Tobi again on the First Stage. In KUNOICHI 8, she failed the Burancho in the First Stage. All four competitors in her group of four failed the first stage, so she got a second chance in the Repechange, but goalkeeper Onodera Shiho was the one to advance to Stage Two. At 13, she is the youngest competitor ever to complete the First Stage in KUNOICHI or SASUKE.
| KUNOICHI 3 | Failed Samenso (First Stage) |
| KUNOICHI 4 | Failed Fuchawatari (First Stage) |
| KUNOICHI 5 | Failed Haso Tobi (First Stage) |
| KUNOICHI 6 | Failed Kenzandou (Third Stage) |
| KUNOICHI 7 | Failed Haso Tobi (First Stage) |
| KUNOICHI 8 | Failed Burancho (First Stage) , Repechange |