Lieutenant Charlotte E. Yeager attempts to become the first witch the break the sound barrier, but Ensign Francesca Lucchini threatens to derail her progress when she accidentally damages Yeager's experimental Striker Unit. Meanwhile, the Strike Witches undergo swimming training at the beach.
Tropes in this episode:
- Clothing Damage: Shirley's bikini disintegrates after reaching Mach-1 and crashing into the Neuroi.
- Erotic Dream: Yoshika starts the episode with one about her and Lynette.
- No Plans, No Prototype, No Backup: A justified example as Lucchini had no idea what she was doing when she put Shirley's Striker Unit back together. She was just hoping it would fly, that her modifications would be what enabled it to reach Mach-1 was a complete fluke. Then it was lost in the ocean immediately afterwards.
- Oh, Crap!:
- Yoshika when she accidentally gropes Sakamoto's breasts.
- Shirley when she realizes she is going to crash into the Neuroi.
- Lucchini when she knocks over Shirley's Striker Unit, pieces fall out, and it starts leaking oil.
- Lucchini again when Minna learns of the former's tampering with Shirley's Striker Unit.
- Skinship Grope: Yoshika to Shirley at the end of the episode.
- Training from Hell: Yoshika and Lynette have Striker Units attached to their legs and are dumped in the ocean where they sink like rocks.
