If you tried Langmate and felt "wait, isn't this kind of a dating app?", or realized "as a guy I can't do anything without paying," that is probably why you searched for a Langmate alternative.
Langmate is a handy way to connect with foreigners living in Japan, but if your goal is making friends, there is a lot of noise. This post covers the honest, not-a-dating-app alternative to Langmate.
You just want friends, but Langmate keeps getting in the way.
If you genuinely want friends, not romance, switching to an app that matches that goal is faster.
Langmate doesn't even have a map. You scroll a list of profiles, but you can't see who is actually near you right now. SewaYou puts the map front and center.
SewaYou is a map-based app. Open the map and real people near you are right there. Because there is no swipe-and-match, there is none of that dating-app pressure. Message someone interesting, and if they are close, meet up at a cafe. That's it.

Compared with Langmate:
Honest downsides: SewaYou is Japan-centric and newer, so the user base isn't as big as the giants. If you specifically want to meet a lot of people for dating, Langmate may fit better. But if you want foreign friends with no hidden agenda, SewaYou is the one you can use with peace of mind.
Good for: people who want genuine foreign friends, not romance. Download SewaYou and open the map.
The honest options beyond #1.
HelloTalk: The language-exchange classic. More study-oriented than friendship, but big user base and a generous free tier. See the best HelloTalk alternative.
Tandem: The approval step keeps spam lower, but the free tier is limited. Compare in the best Tandem alternative and the HelloTalk vs Tandem comparison.
Meetup: Event-based, centered on language cafes and international exchanges. You meet a group from the start, so there is zero one-on-one dating-app feel.
Bumble BFF: Bumble's friend mode. Because it is split from the dating mode, you can use it for friendship. The lack of a nationality filter is the catch.
If Langmate's dating-app feel isn't for you, look at two things: whether the app is truly friendship-first, and whether there is a paywall to message.
Just want friends? SewaYou. Want language practice too? HelloTalk. Pick by goal and you skip the noise.
Is Langmate a dating app? Officially it is a language-exchange and friendship app, but in practice there are plenty of dating-minded users. If you only want friends, a friendship-first app like SewaYou fits better.
Which Langmate alternative lets men message for free? SewaYou has no paywall to message for anyone, men or women. Perfect if Langmate's "men must pay" rule frustrates you.
Is meeting people from a map safe? Meet in public places like cafes, in daylight, the first time. SewaYou even suggests a cafe to meet at, so it is easy to stay comfortable.
Worn out by Langmate's dating-app vibe? SewaYou lets you find friends near you, straight from the map.