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The Ramparts of Ice S1E4 — Impenetrable

7.0

The Ramparts of Ice•Season 1•Episode 4

Impenetrable

7.0/10 · 4 votesApr 23, 202624 min

Ranked #16 of 18 in Season 1•−0.7 vs season avg

At Miki's prodding, Minato clarifies his interest in her best friend. An unexpected visitor triggers Koyuki's bad memories, leading to a harsh outburst.

Directed byShigatsu Yoshikawa

Written byYasuhiro Nakanishi

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Seasons1

Season 1 Episodes18

Lines and Walls still

Lines and Walls

Locksmith still

Locksmith

3+(←)1 still

3+(←)1

Impenetrable still

E4 7.0Now viewing

Impenetrable

Change still

Change

New Semester still

New Semester

Loneliness and Solitude still

Loneliness and Solitude

On Equal Footing still

On Equal Footing

Self-Awareness still

Self-Awareness

Spring still

Spring

Inversion still

Inversion

Thunder still

Thunder

Perception still

Perception

Bombshell still

Bombshell

Clouds and Rain still

Clouds and Rain

Stop and Go still

Stop and Go

True Feelings still

True Feelings

Relief still

Relief

Cast4

Anna Nagase

Anna Nagase

Koyuki Hikawa (voice)

Fuka Izumi

Fuka Izumi

Miki Azumi (voice)

Shoya Chiba

Shoya Chiba

Minato Amamiya (voice)

Satoshi Inomata

Satoshi Inomata

Yota Hino (voice)

Crew12

Y

Yasuhiro Nakanishi

Writer

H

Hideo Maru

Key Animation

J

Jouji Yanase

Animation Director

M

Miki Ogino

Supervising Animation Director

K

Keisuke Nakazawa

Key Animation

M

Mayumi Yamamoto

Key Animation

T

Tan Tian

Background Designer

K

Koichi Ejima

Background Designer

T

Tomo Shinzato

Background Designer

K

Kunihiko Igarashi

Background Designer

S

Sota Tanigawa

Background Designer

M

Momoko Sato

Background Designer

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Episode Summary

"Impenetrable" is episode 4 of The Ramparts of Ice season 1. It scored 7.0/10 from 4 votes, ranking #16 of 18 episodes this season (season average 7.7). Directed by Shigatsu Yoshikawa and written by Yasuhiro Nakanishi, it aired on April 23, 2026.

Next: E5 · Change Best of Season 1