Kyuukyuu Sentai GoGoFive (1999)

It's the 22th sequel of the series from Super Sentai right after Seijuu Sentai Gingaman which is the 21th sequel. If you would like to watch the super sentai series chronologically.

It's the 23th sequel of the series from Super Sentai right after Kyuukyuu Sentai GoGoFive which is the 22th sequel. If you would like to watch the super sentai series chronologically.

Both are older sentai teams (pre-2000) that focuses on a team that is made up of siblings.

Both have the rangers be away for their parents for the most part

Both have a similar approach to realism in terms of monster attacks. Also Goyellow reminds me of ultraman Leo's human form in terms of personality with both being hot heads that go though a lot of training

Both teams have a rescue brigade motif

Both are toku series that are composed of a team of 5. members. They are part of a franchise that tends to have a 6 member but neither season did that.

Both have family rangers
Both are fighting against ancient demons
Both have old mentors
Both feature villains that are related

Both are fighting a dark ancient evil
Both have family rangers
Mother absent
Feature a "red dragon" villain

It's the very first Super Sentai series what made many of it's successors possible. If you want to watch the original first season of the Super Sentai series.

Both shows have Yasuko Kobayashi on the writing staff (she was a sub-writer on GoGoFive and wrote every single episode of both seasons of Amazons), Masashi Taniguchi among the main cast (Go Blue in GoGoFive and Amazon Alpha in Amazons), and put a focus on family dynamics.

Both are written by Junki Takegami (he was co-head writer on R/B) and feature a sibling team that fights monsters while living with a single father.